use build sphinx action from main branch

Author: niksirbi

.github/workflows/docs_build_and_deploy.yml

@@ -27,7 +27,7 @@ jobs:
     name: Build Sphinx Docs
     runs-on: ubuntu-latest
     steps:
-      - uses: neuroinformatics-unit/actions/build_sphinx_docs@smg/doc-dependencies-as-extra
+      - uses: neuroinformatics-unit/actions/build_sphinx_docs@main
         with:
           use-requirements-txt: false