Fix mutation CI

.github/workflows/mutation.yml

@@ -1,23 +1,17 @@
+name: mutation test
+
 on:
   pull_request:
-    paths-ignore:
-      - 'docs/**'
-      - 'README.md'
-      - 'CHANGELOG.md'
-      - '.gitignore'
-      - '.gitattributes'
+    paths: &paths
+      - 'src/**'
+      - 'tests/**'
+      - '.github/workflows/mutation.yml'
+      - 'composer.json'
+      - 'infection.json.dist'
       - 'psalm.xml'
-
   push:
-    paths-ignore:
-      - 'docs/**'
-      - 'README.md'
-      - 'CHANGELOG.md'
-      - '.gitignore'
-      - '.gitattributes'
-      - 'psalm.xml'
-
-name: mutation test
+    branches: ['master']
+    paths: *paths
 
 jobs:
   mutation:
@@ -32,7 +26,6 @@ jobs:
       matrix:
         os:
           - ubuntu-latest
-
         php:
           - 8.1
 
@@ -60,25 +53,11 @@ jobs:
           coverage: pcov
           tools: composer:v2
 
-      - name: Determine composer cache directory
-        run: echo "COMPOSER_CACHE_DIR=$(composer config cache-dir)" >> $GITHUB_ENV
-
-      - name: Cache dependencies installed with composer
-        uses: actions/cache@v6
-        with:
-          path: ${{ env.COMPOSER_CACHE_DIR }}
-          key: php${{ matrix.php }}-composer-${{ hashFiles('**/composer.json') }}
-          restore-keys: |
-            php${{ matrix.php }}-composer-
-
-      - name: Update composer
-        run: composer self-update
-
-      - name: Install dependencies with composer
-        run: composer update --prefer-dist --no-interaction --no-progress --optimize-autoloader --ansi
+      - name: Install Composer dependencies
+        uses: ramsey/composer-install@65e4f84970763564f46a70b8a54b90d033b3bdda # 4.0.0
 
       - name: Run infection
         run: |
-          vendor/bin/roave-infection-static-analysis-plugin -j2 --ignore-msi-with-no-mutations --only-covered
+          vendor/bin/roave-infection-static-analysis-plugin --ignore-msi-with-no-mutations --only-covered
         env:
           STRYKER_DASHBOARD_API_KEY: ${{ secrets.STRYKER_DASHBOARD_API_KEY }}