[Fix] fix timelineActivities on notes and tasks (#17814)

[Fixes
sentry](https://twenty-v7.sentry.io/issues/7238708876/?environment=prod&environment=prod-eu&project=4507072499810304&query=Field%20metadata%20for%20field&referrer=issue-stream&sort=date):
_Field metadata for field "targetTargetPersonId" is missing in object
metadata timelineActivity_

Regression caused by migration of note and task targets - fields were
renamed from personId to targetPersonId, impacting the event names,
while we still expected them in their previous shape.

---------

Co-authored-by: claude[bot] <41898282+claude[bot]@users.noreply.github.com>
Co-authored-by: Félix Malfait <FelixMalfait@users.noreply.github.com>

packages/twenty-server/src/engine/workspace-manager/dev-seeder/core/utils/seed-feature-flags.util.ts

@@ -56,11 +56,6 @@ export const seedFeatureFlags = async ({
         workspaceId: workspaceId,
         value: true,
       },
-      {
-        key: FeatureFlagKey.IS_TIMELINE_ACTIVITY_MIGRATED,
-        workspaceId: workspaceId,
-        value: true,
-      },
       {
         key: FeatureFlagKey.IS_ATTACHMENT_MIGRATED,
         workspaceId: workspaceId,

packages/twenty-server/src/engine/workspace-manager/workspace-migration/constant/default-feature-flags.ts

@@ -1,7 +1,6 @@
 import { FeatureFlagKey } from 'src/engine/core-modules/feature-flag/enums/feature-flag-key.enum';
 
 export const DEFAULT_FEATURE_FLAGS = [
-  FeatureFlagKey.IS_TIMELINE_ACTIVITY_MIGRATED,
   FeatureFlagKey.IS_ATTACHMENT_MIGRATED,
   FeatureFlagKey.IS_NOTE_TARGET_MIGRATED,
   FeatureFlagKey.IS_TASK_TARGET_MIGRATED,