ci: fix install command

Author: KilianTrunk

.github/workflows/test-runner.yml

@@ -81,7 +81,7 @@ jobs:
 
       - name: Generate application key
         run: |
-          php artisan key:generate --ansi
+          php vendor/bin/testbench key:generate --ansi
 
       - name: Run test suite
         run: vendor/bin/pest --parallel --shard=${{ matrix.shard }}/4 --coverage-clover ./coverage.xml