Bump ramsey/composer-install from 3.2.1 to 4.0.0 (#421)

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/mutation.yml

@@ -54,7 +54,7 @@ jobs:
           coverage: pcov
 
       - name: Install Composer dependencies
-        uses: ramsey/composer-install@a8d0d959dab41457692a5e2041bd9b757a119e3f # 3.2.1
+        uses: ramsey/composer-install@65e4f84970763564f46a70b8a54b90d033b3bdda # 4.0.0
 
       - name: Install db.
         uses: yiisoft/actions/install-packages@master