Bugfix/docs versioning v3

[vicenterusso]

Simon made the replacement directly inside the release.yaml. Do you think we can still use it?

     - name: Set Isar Version
        run: echo "ISAR_VERSION=${{ github.ref_name }}" >> $GITHUB_ENV
      - name: Download Binaries
        run: sh tool/download_binaries.sh
      - name: Adjust Version
        run: find . -type f -exec sed -i "s/0.0.0-placeholder/${{ github.ref_name }}/g" {} +

[mrclauss]

As long as we publish to the hosted solution we need this, because I don't run the release.yaml locally when building the dart packages. And we need the same replacement in every doc build. So having this in a separate script would be good