feat: use MariaDB as drop-in replacement for MySQL (#1085)

Author: metacosm

sample-operators/mysql-schema/k8s/mysql-deployment.yaml

@@ -15,12 +15,12 @@ spec:
         app: mysql
     spec:
       containers:
-      - image: mysql:5.6
-        name: mysql
-        env:
-        # Use secret in real usage
-        - name: MYSQL_ROOT_PASSWORD
-          value: password
-        ports:
-        - containerPort: 3306
-          name: mysql
+        - image: mariadb:10.7
+          name: mysql
+          env:
+            # Use secret in real usage
+            - name: MYSQL_ROOT_PASSWORD
+              value: password
+          ports:
+            - containerPort: 3306
+              name: mysql