Remove default feature flag feature (#15587)

## Context
Having rollout feature for new workspaces creates bad experience for new
users and doesn't bring as much value as existing ones anyway. Removing
migration v2 from default feature flag and the whole concept of default
feature flag

packages/twenty-server/src/engine/core-modules/workspace/services/workspace.service.ts

@@ -45,7 +45,6 @@ import {
 import { PermissionsService } from 'src/engine/metadata-modules/permissions/permissions.service';
 import { WorkspaceCacheStorageService } from 'src/engine/workspace-cache-storage/workspace-cache-storage.service';
 import { WorkspaceManagerService } from 'src/engine/workspace-manager/workspace-manager.service';
-import { DEFAULT_FEATURE_FLAGS } from 'src/engine/workspace-manager/workspace-sync-metadata/constants/default-feature-flags';
 import { extractVersionMajorMinorPatch } from 'src/utils/version/extract-version-major-minor-patch';
 
 @Injectable()
@@ -228,11 +227,6 @@ export class WorkspaceService extends TypeOrmQueryService<WorkspaceEntity> {
       activationStatus: WorkspaceActivationStatus.ONGOING_CREATION,
     });
 
-    await this.featureFlagService.enableFeatureFlags(
-      DEFAULT_FEATURE_FLAGS,
-      workspace.id,
-    );
-
     await this.workspaceManagerService.init({
       workspaceId: workspace.id,
       userId: user.id,

packages/twenty-server/src/engine/workspace-manager/workspace-sync-metadata/constants/default-feature-flags.ts

@@ -1,5 +0,0 @@
-import { FeatureFlagKey } from 'src/engine/core-modules/feature-flag/enums/feature-flag-key.enum';
-
-export const DEFAULT_FEATURE_FLAGS = [
-  FeatureFlagKey.IS_WORKSPACE_MIGRATION_V2_ENABLED,
-] as const satisfies FeatureFlagKey[];