Fix workspace relation sync (#11963)

## Context

While deploying the IS_NEW_RELATION_ENABLED (we don't compute relation
based on relationMetadata anymore) to existing workspace, I've tested to
run a sync-metadata post feature flag activation. This has raised two
issues:
- the workspaceMigration generator (which is over-complex and should be
refactored later) for fieldMetadata of type RELATION was not handling
settings update properly ;
- we need to delete existing fieldMetadata corresponding to the UUID
foreignKey as they are not needed anymore. This is handled as a 0.53
upgrade command as 0.53 will also come with the full removal of the old
relation system

---------

Co-authored-by: Etienne <45695613+etiennejouan@users.noreply.github.com>
Co-authored-by: prastoin <paul@twenty.com>

packages/twenty-server/src/engine/workspace-manager/workspace-sync-metadata/services/workspace-metadata-updater.service.ts

@@ -221,8 +221,6 @@ export class WorkspaceMetadataUpdaterService {
       [];
     let updatedFieldRelationMetadataCollection: FieldMetadataUpdate<FieldMetadataType.RELATION>[] =
       [];
-    let deletedFieldRelationMetadataCollection: FieldMetadataUpdate<FieldMetadataType.RELATION>[] =
-      [];
 
     /**
      * Create field relation metadata
@@ -253,20 +251,26 @@ export class WorkspaceMetadataUpdaterService {
     }
 
     if (!options || options.actions.includes('delete')) {
-      deletedFieldRelationMetadataCollection = await this.updateEntities<
-        FieldMetadataEntity<FieldMetadataType.RELATION>
-      >(
-        manager,
-        FieldMetadataEntity,
-        storage.fieldRelationMetadataDeleteCollection,
-        ['objectMetadataId', 'workspaceId'],
-      );
+      const fieldMetadataRepository =
+        manager.getRepository(FieldMetadataEntity);
+
+      if (storage.fieldRelationMetadataDeleteCollection.length > 0) {
+        await fieldMetadataRepository.delete(
+          storage.fieldRelationMetadataDeleteCollection.map(
+            (field) => field.id,
+          ),
+        );
+      }
     }
 
     return {
       createdFieldRelationMetadataCollection,
       updatedFieldRelationMetadataCollection,
-      deletedFieldRelationMetadataCollection,
+      deletedFieldRelationMetadataCollection:
+        storage.fieldRelationMetadataDeleteCollection.map((field) => ({
+          current: field,
+          altered: field,
+        })),
     };
   }