Move default authentication plugin config into my.cnf file

Author: schlessera

.github/workflows/testing.yml

@@ -110,7 +110,7 @@ jobs:
           MYSQL_ROOT_PASSWORD: root
         ports:
           - 3306
-        options: --default-authentication-plugin="mysql_native_password" --health-cmd="mysqladmin ping" --health-interval=10s --health-timeout=5s --health-retries=3
+        options: --health-cmd="mysqladmin ping" --health-interval=10s --health-timeout=5s --health-retries=3
 
     steps:
       - name: Check out source code
@@ -150,6 +150,10 @@ jobs:
         if: steps.check_files.outputs.files_exists == 'true'
         run: COMPOSER_ROOT_VERSION=dev-master composer install --prefer-dist --no-progress --no-suggest
 
+      - name: Configure MySQL server
+        if: steps.check_files.outputs.files_exists == 'true'
+        run: echo -e '[mysqld]\ndefault-authentication-plugin=mysql_native_password' > "$HOME/.my.cnf"
+
       - name: Start MySQL server
         if: steps.check_files.outputs.files_exists == 'true'
         run: sudo systemctl start mysql