modernize msys2 environments

The msys2 action can install packages via pacboy now.
The hack to use clang32 stopped working.

.github/workflows/build-and-test.yml

@@ -173,23 +173,14 @@ jobs:
         shell: msys2 {0}
     strategy:
       matrix:
-        sys: [mingw64, mingw32, ucrt64, clang64, clang32]
+        # clang32 was broken last time I tried in December 27 2024
+        sys: [msys, mingw64, mingw32, ucrt64, clang64]
     steps:
       - uses: msys2/setup-msys2@v2
         with:
           msystem: ${{matrix.sys}}
-          update: true
           path-type: strict
-          install: pactoys
-      - name: setup
-        run: |
-          # Lines stolen from:
-          # https://github.com/msys2/MINGW-packages/blob/56dd3261b3e67c901e45f9314b671ea19104bc0e/.github/workflows/main.yml#L56-L63
-          grep -qF '[clang32]' /etc/pacman.conf || sed -i \
-              '1s|^|[clang32]\nInclude = /etc/pacman.d/mirrorlist.mingw\n|' \
-              /etc/pacman.conf
-          pacman --noconfirm -Suuy
-          pacboy --noconfirm -S --needed clang:p meson:p ninja:p
+          pacboy: gcc:p meson:p ninja:p
       - uses: actions/[email protected]
       - name: build
         run: |