Mergify: create configuration

[jneira]

• closes Consider using a merge bot to make easier pr handling #1150
• It requires:
  • All ci checks green and
  • At least one approved review and
  • merge me label
• It will do:
  • merge the pr with the "smart" strategy
  • delete the pr branch when merged

smart enables Strict Merge but only update one pull request against its base branch at a time. This allows you to e.g., save CI time, as Mergify will queue the mergeable pull requests and update them serially, one at a time.

• possible changes:
  • dont require the merge me label
  • dont delete the pr branch
  • ??? yu can read more about in https://docs.mergify.io

Of course, it requires install the mergify app in the repo

[pepeiborra]

Great idea, thanks @jneira

[pepeiborra]

can we drop this one since the cabal build is already covered by the GitHub Actions?

[jneira]

yeah, maybe we should remove it entirely, but we can start not adding here

[pepeiborra]

I have removed it in #1152

[pepeiborra]

Can we drop this one since it's unclear what ghc-default means?

[jneira]

ghc-default is using the default stack.yaml, without version
maybe we should change the name in ci (and here too, but keeping it in any case)

[pepeiborra]

I have deleted it in #1152

[pepeiborra]

I enabled the Mergify integration with this Github repo, but it needs to be validated by an admin of the Haskell org

[alanz]

Happy with the concept.

And happy with squash or merge as strategy

[Ailrun]

LGTM