Implements one part of forgejo/runner#119. The other part is a corresponding PR in forgejo/runner: forgejo/runner#120.
Reviewed-on: https://code.forgejo.org/forgejo/act/pulls/24
Reviewed-by: earl-warren <earl-warren@noreply.code.forgejo.org>
Co-authored-by: s3lph <codeberg@s3lph.me>
Co-committed-by: s3lph <codeberg@s3lph.me>