Documentation switcher broken

[RobPasMue]

We should be deploying the docs through our Ansys actions, since they are the ones handling the multi-version scheme:

    name: Upload release documentation
    if: github.event_name == 'push' && contains(github.ref, 'refs/heads/release')
    runs-on: ubuntu-latest
    needs: [doc-build]
    steps:
      - name: Deploy the stable documentation
        uses: ansys/actions/doc-deploy-stable@v4
        with:
          cname: ${{ env.DOCUMENTATION_CNAME }}
          token: ${{ secrets.GITHUB_TOKEN }}

However, this project is a bit special... Our versions should be the ones for the API versions.

• I propose we adapt the current workflow to use "common" env variables whenever possible.
• We will then have release branches for the various mechanical API branches.

release/23.1
release/23.2
...

• And they will all be coming out from main.
• Each of these branches will then have to adapt their env variables and container used.
• No docs will be published from the main branch (and thus, no dev target will be available)

[klmcadams]

The documentation versions are not based on the Mechanical version anymore, but the pymechanical-stubs version in the pyproject.toml file