CI quick-jobs: entirely wipe ghcup directory rights workaround

.github/workflows/quick-jobs.yml

@@ -27,16 +27,6 @@ jobs:
         gen-spdx-exc
     # This job is not run in a container, any recent GHC should be fine
     steps:
-      # OBSOLETE: workaround to fix ghcup directory rights.
-      # # See https://github.com/haskell/cabal/pull/8739
-      # - name: Sudo chmod to permit ghcup to update its cache
-      #   if: runner.os == 'Linux'
-      #   run: |
-      #       sudo ls -lah /usr/local/.ghcup/cache
-      #       sudo mkdir -p /usr/local/.ghcup/cache
-      #       sudo ls -lah /usr/local/.ghcup/cache
-      #       sudo chown -R "${USER}" /usr/local/.ghcup
-      #       sudo chmod -R 777 /usr/local/.ghcup
       # SKIP installation of ghc and cabal and use the preinstalled versions.
       # - name: ghcup
       #   run: |