fix(unit-testing.md): Auto mocking is now appropriately typed.

NestJS 11's stricter linting threw a bunch of no-unsafe-* errors. This commit makes the linter happy.

Fixes #3288

Author: codiophile

content/fundamentals/unit-testing.md

@@ -186,7 +186,9 @@ describe('CatsController', () => {
           const mockMetadata = moduleMocker.getMetadata(
             token,
           ) as MockMetadata<any, any>;
-          const Mock = moduleMocker.generateFromMetadata(mockMetadata);
+          const Mock = moduleMocker.generateFromMetadata(
+            mockMetadata,
+          ) as ObjectConstructor;
           return new Mock();
         }
       })