Ask for PHP 8.5 and test one runtime

Nothing in the package needs a feature of either version: the floor sat
at 8.4 because that is where the scaffold put it, and Laravel 13 itself
asks only for 8.3. Two entries in the feature matrix bought a second run
of the same suite on a runtime the code cannot tell apart from the one
beside it.

2.3.0 asks for 8.5. The feature job loses its matrix and runs on 8.5
alone, so pint no longer needs the `if` that kept it from running twice;
the browser jobs were already pinned there. 2.2.0 stays available for an
application still on 8.4.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

composer.json

@@ -20,7 +20,7 @@
         }
     ],
     "require": {
-        "php": "^8.4",
+        "php": "^8.5",
         "laravel/framework": "^13.0",
         "livewire/livewire": "^4.0"
     },