Use phpcs installed with composer instead of php-actions/phpcs

It's unclear which version is actually being installed with this action.
Clearly the current installation is using an older version of phpcs that
did not take constant types into account, and is therefore erroneously
failing the build

.github/workflows/lint.yml

@@ -16,14 +16,13 @@ jobs:
                 with:
                     fetch-depth: 0
 
-            -   name: Install PHP dependencies
-                uses: php-actions/composer@v6
+            -   name: Setup PHP
+                uses: shivammathur/setup-php@v2
                 with:
-                    php_version: 8.3
+                    php-version: '8.3'
+
+            -   name: Install PHP dependencies
+                run: composer install
 
             -   name: Run PHP Code Sniffer
-                uses: php-actions/phpcs@v1
-                with:
-                    php_version: 8.3
-                    path: src/
-                    standard: phpcs.xml
+                run: composer lint