docs: bump mysql version to 8.0.31 for docker documentation (#167)

将 Docker Compose 文档中的 MySQL 版本升级到 8.0.31 以支持 Arm 架构的机器。

/kind documentation

Fixes #135 

```release-note
None
```

docs/getting-started/install/docker-compose.md

@@ -136,7 +136,7 @@ import DockerArgs from "./slots/docker-args.md"
           - --halo.security.initializer.superadminpassword=P@88w0rd
 
       halodb:
-        image: mysql:8.0.27
+        image: mysql:8.0.31
         container_name: halodb
         restart: on-failure:3
         networks:

versioned_docs/version-2.0/getting-started/install/docker-compose.md

@@ -136,7 +136,7 @@ import DockerEnv from "./slots/docker-env.md"
           - HALO_SECURITY_INITIALIZER_SUPERADMINPASSWORD=P@88w0rd
 
       halodb:
-        image: mysql:8.0.27
+        image: mysql:8.0.31
         container_name: halodb
         restart: on-failure:3
         networks:

versioned_docs/version-2.1/getting-started/install/docker-compose.md

@@ -136,7 +136,7 @@ import DockerArgs from "./slots/docker-args.md"
           - --halo.security.initializer.superadminpassword=P@88w0rd
 
       halodb:
-        image: mysql:8.0.27
+        image: mysql:8.0.31
         container_name: halodb
         restart: on-failure:3
         networks: