chore: add workflow step

Author: Ninerian

.github/workflows/php.yml

@@ -2,9 +2,9 @@ name: PHP Composer
 
 on:
   push:
-    branches: [ master ]
+    branches: [ main ]
   pull_request:
-    branches: [ master ]
+    branches: [ main ]
 
 jobs:
   run:
@@ -31,5 +31,8 @@ jobs:
       if: steps.composer-cache.outputs.cache-hit != 'true'
       run: composer update --prefer-dist --no-progress
 
+    - name: Linting
+      run: composer lint
+
     - name: Run test suite
       run: composer test