fix: install mysql client

Author: miguelpeixe

.github/workflows/reusable-test-php.yml

@@ -49,7 +49,7 @@ jobs:
           coverage: pcov
 
       - name: Install system dependencies
-        run: sudo apt-get update && sudo apt-get install -y subversion
+        run: sudo apt-get update && sudo apt-get install -y subversion default-mysql-client
 
       - name: Install Composer dependencies
         run: composer update