Remove 7.1 from the CI matrix because psr/http-message ^2.0 requires 7.2 or later.

Author: kwhat

.github/workflows/ci.yml

@@ -18,7 +18,6 @@ jobs:
           - 7.4
           - 7.3
           - 7.2
-          - 7.1
     steps:
       - uses: actions/checkout@v4
       - uses: shivammathur/setup-php@v2