Use personal access token for git push

[nsoranzo]

in fetch-all-tools-merge job, so it can trigger the "Filter community tools" workflow. See https://docs.github.com/en/actions/using-workflows/triggering-a-workflow#triggering-a-workflow-from-a-workflow

Closes #57 .

[paulzierep]

Thanks @nsoranzo;
I took: https://github.com/galaxyproject/galaxy_tool_metadata_extractor/blob/cea51e857e8839cdd61dfe3dc61e065f084f7c18/.github/workflows/fetch_all_tools.yaml#L40-L42
but otherwise opted for

  # the workflow it triggered when all tools are fetched
  workflow_run:
      workflows: ["Fetch all tools"]
      types:
        - completed

Since it is more implicit.