Completely overhaul Windows CI

[embg]

This PR overhauls our broken Windows tests (cmake, msbuild, and mingw). Fixes #3064. I'm going to break the summary down into three sections:

Visual Studio + cmake

• Upgraded from Visual Studio 2019 to Visual Studio 2022.

Visual Studio + msbuild

• Deleted Visual Studio 2015 test
• Kept Visual Studio 2019 test (release build only, to reduce the total number of jobs)
• Added Visual Studio 2022 test (release + debug)
• Parameterized the job definition so it can be changed more easily in the future
• Upgraded the setup-msbuild version from v1.1.3 to v1.3 (future proofing in case v1.1.3 stops working at some point)

mingw tests

I spent most of my time unbreaking these tests. It took a lot of trial and error: embg#43

The problem is that GitHub's Windows 2022 image removes some of the msys2 packages that were installed by default in Windows 2019. This is a problem because our mingw jobs were written in PowerShell and replied on certain msys2 packages being installed at certain locations. Using msys2 in GitHub actions from PowerShell is an anti-pattern according to msys2 docs: https://www.msys2.org/docs/ci/

The proper way is to use the msys2/setup-msys2 GitHub Action to install msys2 and any required packages (such as make and diffutils). I rewrote the mingw jobs to use msys2 properly, fixing the current breakage and preventing future breakages.

Some notes:

• The mingw-long-test had a build test which was nearly a duplicate of the build test in mingw-short-test. I folded the two build tests together under mingw-short-test, so now mingw-long-test is solely responsible for fuzzing.
• The PowerShell version of mingw-short-test did not fail the overall job in case the build step failed, due to how errors propagage from sh -c to PowerShell. This means the CI job wasn't actually validating the build. I checked that the new setup does fail if the build step fails.