Fix label filtering for labels in bad state

What does this MR do and why?

Labels are supposed to only have a project_id or a group_id. When they have both, filtering does not work due to the extra where clause.

This does not fix the root cause but allows filtering by labels that are in this state

Related to #291034 (closed) https://gitlab.com/gitlab-com/dev-sub-department/section-dev-request-for-help/-/issues/62

Before

SELECT "labels"."title", "labels"."id"
FROM (
  (SELECT "labels".* FROM "labels" WHERE "labels"."project_id" IS NULL AND "labels"."group_id" IN (
    SELECT namespaces.traversal_ids[array_length(namespaces.traversal_ids, 1)] AS id FROM "namespaces" WHERE "namespaces"."type" = 'Group' AND (traversal_ids @> ('{9970}'))
  ) AND "labels"."title" = 'bug'
) UNION ALL (
  SELECT "labels".* FROM "labels" WHERE "labels"."group_id" IS NULL AND "labels"."project_id" IN (
    SELECT "projects"."id" FROM "projects" WHERE "projects"."namespace_id" IN (SELECT namespaces.traversal_ids[array_length(namespaces.traversal_ids, 1)] AS id FROM "namespaces" WHERE "namespaces"."type" = 'Group' AND (traversal_ids @> ('{9970}')))
  ) AND "labels"."title" = 'bug')
) labels

After

SELECT "labels"."title", "labels"."id"
FROM (
  (SELECT "labels".* FROM "labels" WHERE "labels"."group_id" IN (
    SELECT namespaces.traversal_ids[array_length(namespaces.traversal_ids, 1)] AS id FROM "namespaces" WHERE "namespaces"."type" = 'Group' AND (traversal_ids @> ('{9970}'))
  ) AND "labels"."title" = 'bug'
) UNION ALL (
  SELECT "labels".* FROM "labels" WHERE "labels"."project_id" IN (
    SELECT "projects"."id" FROM "projects" WHERE "projects"."namespace_id" IN (SELECT namespaces.traversal_ids[array_length(namespaces.traversal_ids, 1)] AS id FROM "namespaces" WHERE "namespaces"."type" = 'Group' AND (traversal_ids @> ('{9970}')))
  ) AND "labels"."title" = 'bug')
) labels

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