CI: Use 64-bit for Windows build

See also: https://www.msys2.org/news/#2023-12-13-starting-to-drop-some-32-bit-packages

.github/actions/install-dependencies/action.yml

@@ -20,16 +20,31 @@ runs:
     - uses: msys2/setup-msys2@v2
       if: startsWith(inputs.os, 'windows')
       with:
-        msystem: MINGW32
+        msystem: MINGW64
         update: true
         install: >-
-          mingw-w64-i686-autotools mingw-w64-i686-faad2 mingw-w64-i686-ffmpeg
-          mingw-w64-i686-flac mingw-w64-i686-fluidsynth mingw-w64-i686-gcc
-          mingw-w64-i686-gtk2 mingw-w64-i686-lame mingw-w64-i686-libbs2b
-          mingw-w64-i686-libcdio-paranoia mingw-w64-i686-libcue
-          mingw-w64-i686-libmodplug mingw-w64-i686-libopenmpt
-          mingw-w64-i686-libsamplerate mingw-w64-i686-libsidplayfp
-          mingw-w64-i686-libsoxr mingw-w64-i686-libvorbis mingw-w64-i686-meson
-          mingw-w64-i686-mpg123 mingw-w64-i686-neon mingw-w64-i686-opusfile
-          mingw-w64-i686-pkg-config mingw-w64-i686-qt5-base mingw-w64-i686-SDL2
-          mingw-w64-i686-wavpack
+          mingw-w64-x86_64-autotools
+          mingw-w64-x86_64-faad2
+          mingw-w64-x86_64-ffmpeg
+          mingw-w64-x86_64-flac
+          mingw-w64-x86_64-fluidsynth
+          mingw-w64-x86_64-gcc
+          mingw-w64-x86_64-gtk2
+          mingw-w64-x86_64-lame
+          mingw-w64-x86_64-libbs2b
+          mingw-w64-x86_64-libcdio-paranoia
+          mingw-w64-x86_64-libcue
+          mingw-w64-x86_64-libmodplug
+          mingw-w64-x86_64-libopenmpt
+          mingw-w64-x86_64-libsamplerate
+          mingw-w64-x86_64-libsidplayfp
+          mingw-w64-x86_64-libsoxr
+          mingw-w64-x86_64-libvorbis
+          mingw-w64-x86_64-meson
+          mingw-w64-x86_64-mpg123
+          mingw-w64-x86_64-neon
+          mingw-w64-x86_64-opusfile
+          mingw-w64-x86_64-pkg-config
+          mingw-w64-x86_64-qt5-base
+          mingw-w64-x86_64-SDL2
+          mingw-w64-x86_64-wavpack