Bring back the PR Refactor doctests + add CI to main (#23271)

* Revert "Revert "[Doctests] Refactor doctests + add CI" (#23245)"

This reverts commit 69ee46243c.

* try not expose HfDocTestParser

* move into testing_utils.py

* remove pytest install

---------

Co-authored-by: ydshieh <ydshieh@users.noreply.github.com>

.github/workflows/doctests.yml

@@ -37,18 +37,10 @@ jobs:
       - name: Show installed libraries and their versions
         run: pip freeze
 
-      - name: Prepare files for doctests
-        run: |
-          python3 utils/prepare_for_doc_test.py src docs
-
       - name: Run doctests
         run: |
           python3 -m pytest -v --make-reports doc_tests_gpu --doctest-modules $(cat utils/documentation_tests.txt) -sv --doctest-continue-on-failure --doctest-glob="*.mdx"
 
-      - name: Clean files after doctests
-        run: |
-          python3 utils/prepare_for_doc_test.py src docs --remove_new_line
-
       - name: Failure short reports
         if: ${{ failure() }}
         continue-on-error: true