Revert "Fix the MySQL Server version used for testing to (php#14120)"

This reverts commit febbbfa.

Author: SakiTakamachi

.github/workflows/nightly.yml

@@ -161,7 +161,7 @@ jobs:
       image: ubuntu:${{ (matrix.branch.ref == 'PHP-8.3' || matrix.branch.ref == 'master') && '22.04' || '20.04' }}
     services:
       mysql:
-        image: mysql:8.3
+        image: mysql:8
         ports:
           - 3306:3306
         env:

.github/workflows/push.yml

@@ -48,7 +48,7 @@ jobs:
     if: github.repository == 'php/php-src' || github.event_name == 'pull_request'
     services:
       mysql:
-        image: mysql:8.3
+        image: mysql:8
         ports:
           - 3306:3306
         env: