fix(server): invite user type might be null (#4020)

apps/server/src/modules/workspaces/resolver.ts

@@ -198,7 +198,9 @@ export class WorkspaceResolver {
         user: true,
       },
     });
-    return data.map(({ id, accepted, type, user }) => ({
+    return data
+      .filter(({ user }) => !!user)
+      .map(({ id, accepted, type, user }) => ({
         ...user,
         permission: type,
         inviteId: id,