Add organization_id to ldap_admin_role_links

What does this MR do and why?

This change adds an organization_id sharding key to the ldap_admin_role_links table. We currently have 0 rows in production.

select * from ldap_admin_role_links;

 Seq Scan on public.ldap_admin_role_links  (cost=0.00..0.00 rows=1 width=186) (actual time=0.004..0.005 rows=0 loops=1)
   I/O Timings: read=0.000 write=0.000
Settings: effective_cache_size = '472585MB', jit = 'off', random_page_cost = '1.5', seq_page_cost = '4', work_mem = '100MB'

https://console.postgres.ai/gitlab/gitlab-production-main/sessions/44347/commands/135960

update ldap_admin_role_links set organization_id = 1 where organization_id IS NULL;

Time: 0.487 ms
  - planning: 0.410 ms
  - execution: 0.077 ms
    - I/O read: 0.000 ms
    - I/O write: 0.000 ms

Shared buffers:
  - hits: 0 from the buffer pool
  - reads: 0 from the OS file cache, including disk I/O
  - dirtied: 0
  - writes: 0

https://console.postgres.ai/gitlab/gitlab-production-main/sessions/44605/commands/136861

References

• #553464

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