CI bench-unit job failures

[pepeiborra]

The upload of the .cabal folder to the CI cache fails with a 400. Example below:

https://github.com/haskell/haskell-language-server/runs/7818378102?check_suite_focus=true

[pepeiborra]

This is blocking many PRs.

I am not looking into it right now, happy for someone else to grab it