UIY-3913 Fix php version in github workflow

Author: Hofmeister

.github/workflows/test.yml

@@ -12,6 +12,11 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v2
+    - name: Setup PHP with tools
+      uses: shivammathur/setup-php@v2
+      with:
+        php-version: '7.4'
+    - uses: actions/checkout@v2
     - name: Validate composer.json and composer.lock
       run: composer validate
     - name: Cache Composer packages