Add PHP 8.5 to matrix

`nightly` now refers to PHP 8.6.

Fixes #150

Author: swissspidy

.github/workflows/reusable-testing.yml

@@ -198,6 +198,16 @@ jobs:
               "wp": "trunk",
               "dbtype": "sqlite"
             },
+            {
+              "php": "8.5",
+              "wp": "trunk",
+              "mysql": "mysql-8.0"
+            },
+            {
+              "php": "8.5",
+              "wp": "trunk",
+              "dbtype": "sqlite"
+            },
             {
               "php": "nightly",
               "wp": "trunk",