GH Actions: Bump ramsey/composer-install from 3.1.1 to 4.0.0

Bumps [ramsey/composer-install](https://github.com/ramsey/composer-install) from 3.1.1 to 4.0.0.
- [Release notes](https://github.com/ramsey/composer-install/releases)
- [Commits](ramsey/composer-install@3cf229d...65e4f84)

---
updated-dependencies:
- dependency-name: ramsey/composer-install
  dependency-version: 4.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/reusable-phpstan.yml

@@ -58,7 +58,7 @@ jobs:
       # @link https://github.com/marketplace/actions/install-php-dependencies-with-composer
       - name: Install Composer dependencies
         if: ${{ steps.has_config.outputs.files_exists == 'true' }}
-        uses: "ramsey/composer-install@3cf229dc2919194e9e36783941438d17239e8520" # 3.1.1
+        uses: "ramsey/composer-install@65e4f84970763564f46a70b8a54b90d033b3bdda" # 4.0.0
         with:
           # Bust the cache at least once a month - output format: YYYY-MM.
           custom-cache-suffix: $(date -u "+%Y-%m")