PHP 8.1 is stable

Author: adlacruzes

.github/workflows/continuous-integration.yml

@@ -26,6 +26,7 @@ jobs:
           - "7.3"
           - "7.4"
           - "8.0"
+          - "8.1"
         os: [ ubuntu-20.04 ]
 
     steps:

.github/workflows/nightly-build.yml

@@ -20,7 +20,6 @@ jobs:
       fail-fast: false
       matrix:
         php-version:
-          - "8.1"
           - "nightly"
         os: [ ubuntu-latest ]