Don't build an uberjar (#235)

The default jar we've been building since the beginning of the language
server was an uberjar containing all our dependencies. This is also the
jar we published to Maven Central, and (more recently) the jar we have
included in the runtime images.

For publishing and the runtime image, this is definitely wrong. Running
the language server with coursier, which seems common and is also what
the vscode extension currently does, means coursier will resolve and
fetch dependencies for no reason. For the runtime image, it means we
have basically duplicated all the dependency jars, increasing download
size for no reason. Both probably incur a startup penalty too.

I'm guessing the original reason for this was so you could just do a
build and run `java -jar ...` to run the language server. But since we
publish to Maven and have the runtime images, I'm not sure what the
benefit of keeping the uberjar would be, unless people pull it from
Maven without doing dependency resolution.

I decided to just remove the uberjar. If it causes an issue, we can
always bring it back and use the shadow plugin or something.

With this change, we got some moderate install size improvements. Around
12-14% depending on the target:
 windows-x64    49M -> 42M
 darwin-aarch64 50M -> 43M
 darwin-x86_64  51M -> 44M
 linux-aarch64  57M -> 50M
 linux-x86_64   58M -> 51M

Side note: A 40-50M install size still annoyed me, so I did some digging
and tried a few things. Just smithy-cli and smithy-model make up about
6M, while the language server itself and the rest of our deps all
together don't break 3M. Not much we can do here unless the cli changed
what is uses (we do duplicate gson, which is shaded in the CLI, but
it's only like 300K). Another thing I tried was digging into the JDK
modules we link. There's only a few, and they're all quite small, except
for 'java.xml' which is like 3M. Unfortunately we do need that at
runtime according to my tests. Something uses it. The last thing I tried
was increasing the '--compress' jlink option from 6 -> 9, but didn't
notice a difference.

Also in this commit I changed the '--compress' option's value. The value
'2' is deprecated. 'zip-6' is the same level of compression.

Author: milesziemer

build.gradle.kts

@@ -129,18 +129,6 @@ tasks {
         dependsOn(createProperties)
     }
 
-    jar {
-        from(configurations.runtimeClasspath.get().map { zipTree(it) }) {
-            // Don't need signature files, and we don't use modules
-            exclude("META-INF/*.SF", "META-INF/*.DSA", "META-INF/*.RSA", "**/module-info.class")
-            duplicatesStrategy = DuplicatesStrategy.EXCLUDE
-        }
-
-        manifest {
-            attributes("Main-Class" to "software.amazon.smithy.lsp.Main")
-        }
-    }
-
     checkstyleTest {
         enabled = false
     }
@@ -215,7 +203,7 @@ checkstyle {
 }
 
 runtime {
-    addOptions("--compress", "2", "--strip-debug", "--no-header-files", "--no-man-pages")
+    addOptions("--compress", "zip-6", "--strip-debug", "--no-header-files", "--no-man-pages")
     addModules("java.logging", "java.naming", "java.xml", "jdk.crypto.ec")
 
     launcher {