Add FlaxCLIPTextModelWithProjection (#25254)

* Add FlaxClipTextModelWithProjection

This is necessary to support the Flax port of Stable Diffusion XL: fb6d705fb5/text_encoder_2/config.json (L3)

Co-authored-by: Martin Müller <martin.muller.me@gmail.com>
Co-authored-by: Juan Acevedo <juancevedo@gmail.com>

* Use FlaxCLIPTextModelOutput

* make fix-copies again

* Apply suggestions from code review

Co-authored-by: Sanchit Gandhi <93869735+sanchit-gandhi@users.noreply.github.com>

* Use `return_dict` for consistency with other uses.

Co-authored-by: Sanchit Gandhi <93869735+sanchit-gandhi@users.noreply.github.com>

* Fix docstring example.

* Add new model to FlaxCLIPTextModelTest

* Add to IGNORE_NON_AUTO_CONFIGURED list

* Fix naming convention.

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Co-authored-by: Martin Müller <martin.muller.me@gmail.com>
Co-authored-by: Juan Acevedo <juancevedo@gmail.com>
Co-authored-by: Sanchit Gandhi <93869735+sanchit-gandhi@users.noreply.github.com>

utils/check_repo.py

@@ -205,6 +205,7 @@ IGNORE_NON_AUTO_CONFIGURED = PRIVATE_MODELS.copy() + [
     "TFGroupViTTextModel",
     "TFGroupViTVisionModel",
     "FlaxCLIPTextModel",
+    "FlaxCLIPTextModelWithProjection",
     "FlaxCLIPVisionModel",
     "FlaxWav2Vec2ForCTC",
     "DetrForSegmentation",