Enable the @typescript-eslint/no-explicit-any eslint rule (#1830)

## Description:

Enable the `@typescript-eslint/no-explicit-any` eslint rule.

Fixes #1789

## Please complete the following:

- [x] I have added screenshots for all UI updates
- [x] I process any text displayed to the user through translateText()
and I've added it to the en.json file
- [x] I have added relevant tests to the test directory
- [x] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced

src/server/worker/websocket/handler/message/PostJoinHandler.ts

@@ -102,7 +102,7 @@ export async function postJoinMessageHandler(
         break;
       }
       default: {
-        log.warn(`Unknown message type: ${(clientMsg as any).type}`, {
+        log.warn(`Unknown message type: ${clientMsg.type}`, {
           clientID: client.clientID,
         });
         break;