[ci] Switch to windows-2025 image

The windows-2019 image is gone.

Author: khaledhosny

.github/workflows/ci.yml

@@ -17,7 +17,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-latest, ubuntu-24.04-arm, macos-latest, windows-2019]
+        os: [ubuntu-latest, ubuntu-24.04-arm, macos-latest, windows-2025]
 
     steps:
     - uses: actions/checkout@v4