Enable @total-typescript/ts-reset (#1761)

## Description:

Enable `@total-typescript/ts-reset`

Fixes #1760

## 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
- [ ] I have read and accepted the CLA agreement (only required once).

src/core/game/FetchGameMapLoader.ts

@@ -1,5 +1,6 @@
 import { GameMapType } from "./Game";
 import { GameMapLoader, MapData } from "./GameMapLoader";
+import { MapManifestSchema } from "./TerrainMapLoader";
 
 export class FetchGameMapLoader implements GameMapLoader {
   private maps: Map<GameMapType, MapData>;
@@ -66,6 +67,6 @@ export class FetchGameMapLoader implements GameMapLoader {
       throw new Error(`Failed to load ${url}: ${response.statusText}`);
     }
 
-    return response.json();
+    return response.json().then(MapManifestSchema.parse);
   }
 }