Add Wav2Vec2Conformer (#16812)

* save intermediate

* add wav2vec2 conformer

* add more code

* more

* first test passes

* make all checkpoints work

* update

* up

* more clean ups

* save clean-up

* save clean-up

* save more

* remove bogus

* finalize design conformer

* remove vision

* finish all tests

* more changes

* finish code

* add doc tests

* add slow tests

* fix autoconfig test

* up

* correct docstring

* up

* update

* fix

* Apply suggestions from code review

Co-authored-by: Sylvain Gugger <35901082+sgugger@users.noreply.github.com>
Co-authored-by: Anton Lozhkov <aglozhkov@gmail.com>

* Update docs/source/en/model_doc/wav2vec2-conformer.mdx

* upload

* save copied from

* correct configs

* fix model outputs

* add to docs

* fix imports

* finish

* finish code

* correct copied from

* correct again

* correct make fix

* improve make fix copies

* save

* correct fix copy from

* correct init structure

* correct

* fix import

* apply suggestions

Co-authored-by: Sylvain Gugger <35901082+sgugger@users.noreply.github.com>
Co-authored-by: Anton Lozhkov <aglozhkov@gmail.com>

docs/source/en/_toctree.yml

@@ -366,6 +366,8 @@
       title: VisualBERT
     - local: model_doc/wav2vec2
       title: Wav2Vec2
+    - local: model_doc/wav2vec2-conformer
+      title: Wav2Vec2-Conformer
     - local: model_doc/wav2vec2_phoneme
       title: Wav2Vec2Phoneme
     - local: model_doc/wavlm