WIP: Switch to testing the mingw configuration on windows-11-arm

Author: mstorsjo

.github/workflows/libcxx-build-and-test.yaml

@@ -224,20 +224,12 @@ jobs:
             **/crash_diagnostics/*
 
   windows:
-    runs-on: windows-2022
+    runs-on: windows-11-arm
     strategy:
       fail-fast: false
       matrix:
         include:
-        - { config: clang-cl-dll, mingw: false }
-        - { config: clang-cl-static, mingw: false }
-        - { config: clang-cl-no-vcruntime, mingw: false }
-        - { config: clang-cl-debug, mingw: false }
-        - { config: clang-cl-static-crt, mingw: false }
         - { config: mingw-dll, mingw: true }
-        - { config: mingw-static, mingw: true }
-        - { config: mingw-dll-i686, mingw: true }
-        - { config: mingw-incomplete-sysroot, mingw: true }
     steps:
       - uses: actions/checkout@v4
       - name: Install dependencies
@@ -251,7 +243,7 @@ jobs:
       - name: Install llvm-mingw
         if: ${{ matrix.mingw == true }}
         run: |
-          curl -LO https://github.com/mstorsjo/llvm-mingw/releases/download/20250114/llvm-mingw-20250114-ucrt-x86_64.zip
+          curl -LO https://github.com/mstorsjo/llvm-mingw/releases/download/20250114/llvm-mingw-20250114-ucrt-aarch64.zip
           powershell Expand-Archive llvm-mingw*.zip -DestinationPath .
           del llvm-mingw*.zip
           mv llvm-mingw* c:\llvm-mingw