chore(tests): align test names with idiomatic naming style (#55496)

Author: kauffinger

tests/Config/RepositoryTest.php

@@ -280,7 +280,7 @@ public function testOffsetUnset()
         $this->assertNull($this->repository->get('associate'));
     }
 
-    public function testsItIsMacroable()
+    public function testItIsMacroable()
     {
         $this->repository->macro('foo', function () {
             return 'macroable';

tests/Database/DatabaseEloquentModelTest.php

@@ -3223,7 +3223,7 @@ public function testCastsMethodIsTakenInConsiderationOnSerialization()
         $this->assertEquals(1, $model->getAttribute('duplicatedAttribute'));
     }
 
-    public function testsCastOnArrayFormatWithOneElement()
+    public function testCastOnArrayFormatWithOneElement()
     {
         $model = new EloquentModelCastingStub;
         $model->setRawAttributes([