Fixed minor issue in GitHub Action's workflow file

Author: divineniiquaye

.github/workflows/tests.yml

@@ -9,7 +9,7 @@ jobs:
       fail-fast: false
       matrix:
         operating-system: [ubuntu-latest, windows-latest, macos-latest]
-        php-versions: ['7.2', '7.3', 7.4', '8.0', '8.1']
+        php-versions: ['7.2', '7.3', '7.4', '8.0', '8.1']
 
     runs-on: ${{ matrix.operating-system }}