For those writing Haskell @github actions, be careful. There is actions/haskell-setup (old, outdated, wrong) and haskell/actions/setup (new). If you use the wrong one you'll never get any newer GHC releases like 8.10.3. I had it wrong, and have just switched all my repos.
https://twitter.com/ndm_haskell/status/1355994676730486787
https://github.com/BlockScope/flare-timing/blob/efc2544d8a14c69c149b2e1b68b2d4a380303faf/.github/workflows/cabal.yml#L24