Deprecated set-output method

[mareknovotny]

According WARNING in one of Chain Status worklfow the andstor/file-existence-action@v1 uses deprecated command set-output

 Run andstor/file-existence-action@v1
  with:
    files: ./current-project/data
    ignore_case: false
    follow_symbolic_links: true
    allow_failure: false
  env:
    PUBLIC_URL: https://kiegroup.github.io/optaplanner
    NPM_CONFIG_USERCONFIG: /home/runner/work/_temp/.npmrc
    NODE_AUTH_TOKEN: XXXXX-XXXXX-XXXXX-XXXXX
🎉 All files exist

Warning: The `set-output` command is deprecated and will be disabled soon. Please upgrade to using Environment Files. For more information see: https://github.blog/changelog/2022-10-11-github-actions-deprecating-save-state-and-set-output-commands/