.github/workflows/test.yml: build on PHP 8.1-8.5

Author: zozlak

.github/workflows/test.yml

@@ -5,6 +5,9 @@ on: push
 jobs:
   phpunit:
     runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        php: [8.1, 8.2, 8.3, 8.4, 8.5]
     steps:
     - uses: actions/checkout@v4
     - uses: actions/cache@v4