Update file(s) from wp-cli/.github

Author: schlessera

.github/workflows/testing.yml

@@ -59,7 +59,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        php: ['5.6', '7.0', '7.1', '7.2', '7.3', '7.4', '8.0']
+        php: ['5.6', '7.0', '7.1', '7.2', '7.3', '7.4', '8.0', '8.1']
         wp: ['latest']
         mysql: ['8.0']
         include: