Fix GitHub workflow scripts

[L-TChen]

It doesn't seem possible to use strategy.matrix to specify what OS to run. So, instead, there are two separate jobs for Ubuntu and for Windows. Moreover, the GitHub Action mstksg/setup-stack does not support Windows despite what it claims (see here), so it doesn't make sense to use the same steps on different OS environments.

For some compatibility issue, I put an additional stack-8.8.3.yaml so that in the future it is easier to run workflows for different GHC versions if you'd like.

Due to a GHC bug, it fails to install Hakyll on Windows for some mysterious reason while building SHA:

SHA > Access violation in generated code when writing 0x0

[LaurentRDC]

You can definitely combine all steps for both operating systems (see here). In this case, don't use the setup-stack action, but rather the setup-haskell action like so:

    # https://github.com/actions/setup-haskell
    - uses: actions/setup-haskell@v1.1
      name: Setup Haskell Stack
      with:
        stack-version: "latest"
        enable-stack: true
        stack-no-global: true

[L-TChen]

Interesting. so mstksg/setup-stack can simply be replaced by actions/setup-haskell completely. Then it makes sense.

Do you have an updated script? If so, I’d like to close mine.

[LaurentRDC]

Ok I'll update the CI script with what I have described above, and will create a new PR.