* Avoid templating GitHub Actions workflow

GitHub Actions workflow have sufficient power to express what we need.
We don't need to maintain and additional templating solution on top.

* Add GHC 9.2, bump bounds, fix syntax

* Switch to official haskell image

* Always run cli tests for ghc 8.2 and above

* Remove step to regenerate GitHub Actions workflows

* Fix missed reference to GHC version

* Fix yaml syntax

* Fix type in the GHC version

* More CI changes

- Run bootstrap.yml on ubuntu-latest
- Use explicit matrix for linux.yml
- Drop containers in favour of haskell setup action
- Drop workaround for ancient git

* Remove unneeded package from CI setup

I belive this is only necessary to run `cabal man` which we do not in
the CI.

* Drop old GHCs from the CI

* Switch macos.yml to haskell/action/setup

Also add the same GHC versions as Linux.

* Simplify CI

- Remove cabal-plan, we actually never call it (I think)
- Remove vendored cabal-doctest
- Remove few stray allow-newer clauses no longer necessary, apparently

Originally done by @gbaz in PR #7907.

* Mark GHC 9.2.1 as experimental

* Remove reference to cabal-plan from validate.sh

* setup-haskell action already runs cabal update

* Add missing build matrix in test-windows-dogfood

* Replace cabal-plan list-bin with cabal list-bin

* Enable caching in the CI

* Fix typo

* Remove continue-on-error until I figure it out

* Keep naming consistent

* Temporarily disable 8.0.2 on macos

* Add missing step id

* Tweaks

Remove workaround for nektos/act, it accidentally sneaked in.

* More tweaks

* Tweaks

* Restore cabal-plan, temporarily mark everything experimental

cabal list-bin doesn't seem to work like cabal-plan does.

* Tweaks

* Ensure cabal-plan executable gets built

* Install automake on MacOS

* Tweaks

* Tweaks

Link experimental flags to relative GitHub issues

* Fix typo

Add the missing space in error messages like:
```
  (conflict: requires NumDecimalswhich is not supported)
```

because we do not provide sandbox functionality anymore

* Backtrack when no pkgconfigdb is present

* changelog and test

* one more test

Co-authored-by: Gershom Bazerman <gershom@arista.com>
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

* solver: swap catas with recursion, fuse travs

* whoops

* add traverseWithKey to cabal-install-solver (#7533)

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

* replace sequence . mapWithKey with traverseWithKey

* more sequence -> traverse

* Update Preference.hs

fix bad merge

* Update Solver.hs

Co-authored-by: Gershom Bazerman <gershom@arista.com>
Co-authored-by: Emily Pillmore <emilypi@cohomolo.gy>
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

- regenerate bootstrap plans
- update CI and docker images for 8.8.4 and 8.10.4

Add unit tests for the `MessageUtils` module in the cabal-install-solver package.

Fail reason now includes suggestions for misspelled language extensions
and language standard.

* Add Setup.hs for `cabal-install-solver`
* Update `cabal.project` pkg path for `cabal-install-solver`