Exclude PHP 8.x for WP 4.7.

Author: desrosj

.github/workflows/upgrade-testing.yml

@@ -358,6 +358,8 @@ jobs:
             db-version: '9.6'
           - php: '7.3'
             db-version: '9.6'
+          - php: [ '8.0', '8.1', '8.2', '8.3', '8.4', '8.5' ]
+            wp: '4.7'
     with:
       os: ${{ matrix.os }}
       php: ${{ matrix.php }}