fix: added 7.4 to test matrix

Author: hallas

.github/workflows/run-tests.yml

@@ -11,7 +11,7 @@ jobs:
       fail-fast: true
       matrix:
         os: [ubuntu-latest, windows-latest]
-        php: [7.3, 8.0]
+        php: [7.4, 8.0]
         stability: [prefer-lowest, prefer-stable]
 
     name: P${{ matrix.php }} - ${{ matrix.stability }} - ${{ matrix.os }}