Merge pull request #3 from stefanzweifel/php81

Run test suite on PHP 8.1

Author: stefanzweifel

.github/workflows/run-tests.yml

@@ -9,7 +9,7 @@ jobs:
       fail-fast: true
       matrix:
         os: [ubuntu-latest]
-        php: [8.0]
+        php: [8.0, 8.1]
         stability: [prefer-lowest, prefer-stable]
 
     name: P${{ matrix.php }} - ${{ matrix.stability }} - ${{ matrix.os }}