Move Threading enum from spring-boot-autoconfigure to spring-boot

The enum itself is not specifically tied to auto-configuration so
spring-boot is a better place for it. The related condition,
`@ConditionalOnThreading`, remains in spring-boot-autoconfigure. This
aligns things with the similar `CloudPlatform` and
`@ConditionalOnCloudPlatform`.

Closes gh-46406

Author: wilkinsona

core/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/condition/ConditionalOnThreading.java

@@ -22,7 +22,7 @@
 import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
 
-import org.springframework.boot.autoconfigure.thread.Threading;
+import org.springframework.boot.thread.Threading;
 import org.springframework.context.annotation.Conditional;
 
 /**

core/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/condition/OnThreadingCondition.java

@@ -18,7 +18,7 @@
 
 import java.util.Map;
 
-import org.springframework.boot.autoconfigure.thread.Threading;
+import org.springframework.boot.thread.Threading;
 import org.springframework.context.annotation.Condition;
 import org.springframework.context.annotation.ConditionContext;
 import org.springframework.core.env.Environment;

core/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/task/TaskExecutorConfigurations.java

@@ -26,11 +26,11 @@
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnThreading;
-import org.springframework.boot.autoconfigure.thread.Threading;
 import org.springframework.boot.task.SimpleAsyncTaskExecutorBuilder;
 import org.springframework.boot.task.SimpleAsyncTaskExecutorCustomizer;
 import org.springframework.boot.task.ThreadPoolTaskExecutorBuilder;
 import org.springframework.boot.task.ThreadPoolTaskExecutorCustomizer;
+import org.springframework.boot.thread.Threading;
 import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Conditional;

core/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/task/TaskSchedulingConfigurations.java

@@ -23,11 +23,11 @@
 import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnThreading;
-import org.springframework.boot.autoconfigure.thread.Threading;
 import org.springframework.boot.task.SimpleAsyncTaskSchedulerBuilder;
 import org.springframework.boot.task.SimpleAsyncTaskSchedulerCustomizer;
 import org.springframework.boot.task.ThreadPoolTaskSchedulerBuilder;
 import org.springframework.boot.task.ThreadPoolTaskSchedulerCustomizer;
+import org.springframework.boot.thread.Threading;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.core.task.TaskDecorator;

core/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/condition/ConditionalOnThreadingTests.java

@@ -20,8 +20,8 @@
 import org.junit.jupiter.api.condition.EnabledForJreRange;
 import org.junit.jupiter.api.condition.JRE;
 
-import org.springframework.boot.autoconfigure.thread.Threading;
 import org.springframework.boot.test.context.runner.ApplicationContextRunner;
+import org.springframework.boot.thread.Threading;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 

core/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/thread/Threading.java renamed to core/spring-boot/src/main/java/org/springframework/boot/thread/Threading.java

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package org.springframework.boot.autoconfigure.thread;
+package org.springframework.boot.thread;
 
 import org.springframework.boot.system.JavaVersion;
 import org.springframework.core.env.Environment;

core/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/thread/package-info.java renamed to core/spring-boot/src/main/java/org/springframework/boot/thread/package-info.java

@@ -17,4 +17,4 @@
 /**
  * Classes related to threads.
  */
-package org.springframework.boot.autoconfigure.thread;
+package org.springframework.boot.thread;

module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/autoconfigure/RabbitAnnotationDrivenConfiguration.java

@@ -31,7 +31,7 @@
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnThreading;
-import org.springframework.boot.autoconfigure.thread.Threading;
+import org.springframework.boot.thread.Threading;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.core.task.VirtualThreadTaskExecutor;

module/spring-boot-data-redis/src/main/java/org/springframework/boot/data/redis/autoconfigure/JedisConnectionConfiguration.java

@@ -27,10 +27,10 @@
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnThreading;
-import org.springframework.boot.autoconfigure.thread.Threading;
 import org.springframework.boot.context.properties.PropertyMapper;
 import org.springframework.boot.ssl.SslBundle;
 import org.springframework.boot.ssl.SslOptions;
+import org.springframework.boot.thread.Threading;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.core.task.SimpleAsyncTaskExecutor;

module/spring-boot-data-redis/src/main/java/org/springframework/boot/data/redis/autoconfigure/LettuceConnectionConfiguration.java

@@ -36,11 +36,11 @@
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnThreading;
-import org.springframework.boot.autoconfigure.thread.Threading;
 import org.springframework.boot.data.redis.autoconfigure.RedisProperties.Lettuce.Cluster.Refresh;
 import org.springframework.boot.data.redis.autoconfigure.RedisProperties.Pool;
 import org.springframework.boot.ssl.SslBundle;
 import org.springframework.boot.ssl.SslOptions;
+import org.springframework.boot.thread.Threading;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.core.task.SimpleAsyncTaskExecutor;