Load sub-configs from composite configs (#34410)

* save/load sub-configs

* nit forgot these

* fix copies

* move test to common

* use dict for sub-configs

* add load-save-laod test

* clean up modeling check

* oops this are correct keys

* fix some tests, missed some composite configs

* this model was missed

tests/models/instructblip/test_modeling_instructblip.py

@@ -486,6 +486,15 @@ class InstructBlipForConditionalGenerationDecoderOnlyTest(ModelTesterMixin, Gene
 
     def setUp(self):
         self.model_tester = InstructBlipForConditionalGenerationDecoderOnlyModelTester(self)
+        self.config_tester = ConfigTester(
+            self,
+            config_class=InstructBlipConfig,
+            has_text_modality=False,
+            common_properties=["num_query_tokens", "image_token_index"],
+        )
+
+    def test_config(self):
+        self.config_tester.run_common_tests()
 
     def test_for_conditional_generation(self):
         config_and_inputs = self.model_tester.prepare_config_and_inputs()