fix: standardize GraphQL schema UUID field types (#13550)

Closes [#1264](https://github.com/twentyhq/core-team-issues/issues/1264)

packages/twenty-server/src/engine/core-modules/feature-flag/feature-flag.entity.ts

@@ -28,7 +28,7 @@ export class FeatureFlag {
   @Column({ nullable: false, type: 'text' })
   key: FeatureFlagKey;
 
-  @Field()
+  @Field(() => UUIDScalarType)
   @Column({ nullable: false, type: 'uuid' })
   workspaceId: string;