Update CI

Author: Rayn93

.github/workflows/ci.yml

@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        php: ['7.3', '8.1']
+        php: ['8.1']
         deps: ['lowest', 'stable']
     steps:
       - name: Checkout code