Fix ugly labels caused by b804f9c6fa

When the test method name is solely 'test()' the output is:
<issue> <className>.()

Consistently modified a few tests to use the generic name 'testit()'.

its/core-it-suite/src/test/java/org/apache/maven/it/MavenITmng5389LifecycleParticipantAfterSessionEnd.java

@@ -31,7 +31,7 @@ public class MavenITmng5389LifecycleParticipantAfterSessionEnd
         super( "[3.2.1,)" );
     }
 
-    public void test()
+    public void testit()
         throws Exception
     {
         File testDir =

its/core-it-suite/src/test/java/org/apache/maven/it/MavenITmng5669ReadPomsOnce.java

@@ -45,7 +45,7 @@ public class MavenITmng5669ReadPomsOnce
         super( "[3.7.0,)" );
     }
 
-    public void test()
+    public void testit()
         throws Exception
     {
         // prepare JavaAgent

its/core-it-suite/src/test/java/org/apache/maven/it/MavenITmng5768CliExecutionIdTest.java

@@ -32,7 +32,7 @@ public class MavenITmng5768CliExecutionIdTest
         super( "(3.2.5,)" );
     }
 
-    public void test()
+    public void testit()
         throws Exception
     {
         File testDir = ResourceExtractor.simpleExtractResources( getClass(), "/mng-5768-cli-execution-id" );