Add PHP 8.4, update Windows to 2025, and checkout to v5

Co-authored-by: clue <[email protected]>

Author: Copilot

.github/workflows/ci.yml

@@ -12,8 +12,9 @@ jobs:
       matrix:
         os:
           - ubuntu-24.04
-          - windows-2022
+          - windows-2025
         php:
+          - 8.4
           - 8.3
           - 8.2
           - 8.1
@@ -24,7 +25,7 @@ jobs:
           - 7.1
           - 7.0
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: shivammathur/setup-php@v2
         with:
           php-version: ${{ matrix.php }}