ci: update workflows for PHP 8.4/8.5 and Laravel 12/13

- run-tests: drop PHP 8.3 and Laravel 11 from the matrix
- phpstan: run against PHP 8.5

https://claude.ai/code/session_01R4pAjWwGY8xKspsdU8xnsy

Author: claude

.github/workflows/phpstan.yml

@@ -16,7 +16,7 @@ jobs:
       - name: Setup PHP
         uses: shivammathur/setup-php@v2
         with:
-          php-version: '8.3'
+          php-version: '8.5'
           coverage: none
 
       - name: Install composer dependencies

.github/workflows/run-tests.yml

@@ -14,12 +14,10 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest]
-        php: [8.5, 8.4, 8.3]
-        laravel: ['13.*', '12.*', '11.*']
+        php: [8.5, 8.4]
+        laravel: ['13.*', '12.*']
         stability: [prefer-lowest, prefer-stable]
         include:
-          - laravel: 11.*
-            testbench: 9.17.0
           - laravel: 12.*
             testbench: 10.*
           - laravel: 13.*