Test against php 8.1 in not experimental mode

Co-authored-by: Adrien Crivelli <[email protected]>

Author: Sergiy Petrov

.github/workflows/main.yml

@@ -12,10 +12,7 @@ jobs:
           - '7.3'
           - '7.4'
           - '8.0'
-
-        include:
-          - php-version: '8.1'
-            experimental: true
+          - '8.1'
 
     name: PHP ${{ matrix.php-version }}