Java: fix PsiClass.getScope() method which was broken by the migration to the new stubs api (IDEA-376896)

GitOrigin-RevId: e204142d2cd57a6cdb83285064ec21fe15b8270b

java/java-tests/testData/ig/com/siyeh/igtest/performance/class_initializer_may_be_static/NoStaticInInnerClass.java

@@ -0,0 +1,12 @@
+class NoStaticInInnerClass {
+
+  {
+    new Inner();
+  }
+  
+  class Inner {
+    {
+      System.out.println("Sunshine and happiness");
+    }
+  }
+}

java/java-tests/testData/ig/com/siyeh/igtest/performance/method_may_be_static/MethodMayBeStatic.java

@@ -97,4 +97,11 @@ class WithArrayReference {
   private void <warning descr="Method 'foo()' may be 'static'">foo</warning>() {
     IntSupplier aNew = Object[]::new;
   }
+}
+class InnerClassScope {
+  class Inner {}
+  
+  Inner create() {
+    return new Inner();
+  }
 }