chore(deps): update mysql docker tag to v9

Author: renovate[bot]

.travis/docker-compose.yml

@@ -28,7 +28,7 @@ services:
       - ../public/assets/:/app/public/assets
 
   mysql:
-    image: mysql:5.7
+    image: mysql:9.5
     environment:
       MYSQL_ALLOW_EMPTY_PASSWORD: "yes"
     ports:

docker-compose.yml

@@ -50,7 +50,7 @@ services:
       - 5900:5900
 
   db:
-    image: mysql:5.7
+    image: mysql:9.5
     container_name: mysql
     environment:
       MYSQL_ALLOW_EMPTY_PASSWORD: "yes"