GHA: skip some msys2 jobs

Author: nulano

.github/workflows/test-msys2.yml

@@ -16,11 +16,13 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - msystem: "UCRT64"
           - msystem: "CLANG64"
-          - msystem: "CLANG32"
           - msystem: "MINGW64"
-          - msystem: "MINGW32"
+          # skip some subsystems to save CI time:
+          # see https://github.com/python-pillow/Pillow/pull/6888#issuecomment-1400392821
+          # - msystem: "UCRT64"
+          # - msystem: "CLANG32"
+          # - msystem: "MINGW32"
 
     defaults:
       run: