GH-1082 - ApplicationModuleSource now uses JavaPackage.findAnnotation(…).

This is to make sure that marker types annotated with @PackageInfo are considered, too. Deprecate JavaPackage.getAnnotation(…) as it's not used anywhere anymore and we would like to consistently consider package info marker types when looking up package annotations.

spring-modulith-integration-test/src/test/java/org/springframework/modulith/core/JavaPackageUnitTests.java

@@ -53,7 +53,7 @@ class JavaPackageUnitTests {
 	void findsAnnotationOnPackageInfo() {
 
 		var annotation = JavaPackage.of(Classes.of(PKG_CLASSES), "pkg.onpackage") //
-				.getAnnotation(ApplicationModule.class);
+				.findAnnotation(ApplicationModule.class);
 
 		assertThat(annotation).hasValueSatisfying(it -> {
 			assertThat(it.displayName()).isEqualTo("onPackage");