CI: hadrian-multi job should not be run for fast-ci label

See https://gitlab.haskell.org/ghc/ghc/-/pipelines/60676

hadrian-multi job fails (https://gitlab.haskell.org/ghc/ghc/-/jobs/1276888#L236) with

tar: ghc-x86_64-linux-fedora33-release.tar.xz: Cannot open: No such file or directory
tar: Error is not recoverable: exiting now

which is kinda expected: MRs with fast-ci label have no x86_64-linux-fedora33-release job to generate this artifact.