Upgrade msys2 to 2026-03-22 release (#619)

Author: swebb2066

.github/workflows/log4cxx-msys2.yml

@@ -48,7 +48,7 @@ jobs:
           cxx: g++
 
     steps:
-    - uses: msys2/setup-msys2@v2
+    - uses: msys2/setup-msys2@cafece8e6baf9247cf9b1bf95097b0b983cc558d # 2.31.0, Mar 23, 2026
       with:
         msystem: ${{matrix.sys}}
         update: true