Try using UCRT64 for Windows build

Author: jlaine

.github/workflows/build-ffmpeg.yml

@@ -32,12 +32,14 @@ jobs:
           - os: ubuntu-24.04
             arch: x86_64
             shell: bash
-          - os: windows-latest
-            arch: AMD64
-            shell: 'msys2 {0}'
           - os: ubuntu-24.04-arm
             arch: aarch64
             shell: bash
+          - os: windows-latest
+            arch: AMD64
+            shell: 'msys2 {0}'
+            msys_sys: ucrt64
+            msys_env: ucrt-x86_64
     defaults:
       run:
         shell: ${{ matrix.shell }}
@@ -54,12 +56,13 @@ jobs:
         run: |
           brew update
           brew unlink gettext libidn2 libpng libtiff libunistring libx11 libxau libxcb libxdmcp little-cms2 unbound
-      - uses: msys2/setup-msys2@c52d1fa9c7492275e60fe763540fb601f5f232a1
+      - uses: msys2/setup-msys2@v2
         if: matrix.os == 'windows-latest'
         with:
-          install: base-devel mingw-w64-x86_64-gcc mingw-w64-x86_64-gperf mingw-w64-x86_64-nasm openssl-devel
+          install: base-devel mingw-${{ matrix.msys_env }}-cc mingw-${{ matrix.msys_env }}-gperf mingw-${{ matrix.msys_env }}-nasm openssl-devel
           path-type: inherit
           release: false
+          system: ${{ matrix.msys_sys }}
       - name: Build FFmpeg
         env:
           CIBW_ARCHS: ${{ matrix.arch }}