Various `cabal-testsuite` improvements (#10225)

* Improve bat scripts for CCompilerOverride

* Ensure Windows tests can cleanup the temp directory

* Implement `flaky` combinator

* Remove outdated tests

* Remove broken tests

These tests were testing for messages that were removed with the `cabal check` rework.

* Make `skip` and `broken` messages uniform

* Mark flaky tests

* Re-enable DeterministicTrivial

* Fix MacOS canonical paths

* Extend cabal-testsuite readme with `flaky`

* Skip non-terminating tests in Windows CI

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