Fix syntax issues in auth.guard.ts

Corrected spacing around type annotation and added missing semicolon in the `canActivate` method. These changes ensure better code consistency and adhere to TypeScript style guidelines.

apps/backend/src/app/auth/auth.guard.ts

@@ -120,7 +120,7 @@ export class InsertAdminState implements CanActivate {
 			return true;
 		}
 
-		request.headers.is_admin = true
+		request.headers.is_admin = true;
 
 		return true;
 	}