Core: Fix Object::has_method() for script static methods

modules/gdscript/tests/scripts/runtime/features/static_method_as_callable.gd

@@ -0,0 +1,12 @@
+# GH-79521
+
+class_name TestStaticMethodAsCallable
+
+static func static_func() -> String:
+	return "Test"
+
+func test():
+	var a: Callable = TestStaticMethodAsCallable.static_func
+	var b: Callable = static_func
+	prints(a.call(), a.is_valid())
+	prints(b.call(), b.is_valid())

modules/gdscript/tests/scripts/runtime/features/static_method_as_callable.out

@@ -0,0 +1,3 @@
+GDTEST_OK
+Test true
+Test true