Remove Roberta Dependencies from XLM Roberta Flax and Tensorflow models (#21047)

* Added flax model code

* Added tf changes

* missed some

* Added copy comments

* Added style hints

* Fixed copy statements

* Added suggested fixes

* Made some fixes

* Style fixup

* Added necessary copy statements

* Fixing copy statements

* Added more copies

* Final copy fix

* Some bugfixes

* Adding imports to init

* Fixed up all make fixup errors

* Fixed doc errors

* Auto model changes

docs/source/en/model_doc/xlm-roberta.mdx

@@ -146,6 +146,11 @@ A list of official Hugging Face and community (indicated by 🌎) resources to h
 [[autodoc]] TFXLMRobertaModel
     - call
 
+## TFXLMRobertaForCausalLM
+
+[[autodoc]] TFXLMRobertaForCausalLM
+    - call
+
 ## TFXLMRobertaForMaskedLM
 
 [[autodoc]] TFXLMRobertaForMaskedLM
@@ -176,6 +181,11 @@ A list of official Hugging Face and community (indicated by 🌎) resources to h
 [[autodoc]] FlaxXLMRobertaModel
     - __call__
 
+## FlaxXLMRobertaForCausalLM
+
+[[autodoc]] FlaxXLMRobertaForCausalLM
+    - __call__
+
 ## FlaxXLMRobertaForMaskedLM
 
 [[autodoc]] FlaxXLMRobertaForMaskedLM