Fix missing `traversal_ids` for `vulnerability_reads` records

What does this MR do and why?

This migration sets the missing traversal_ids for the vulnerability_reads records. As of writing, there are 172 records in this condition on the production database.

Initial batching query

SELECT
    "vulnerability_reads"."vulnerability_id"
FROM
    "vulnerability_reads"
WHERE
    "vulnerability_reads"."traversal_ids" = '{}'
    AND "vulnerability_reads"."archived" = FALSE
ORDER BY
    "vulnerability_reads"."vulnerability_id" ASC
LIMIT 1

https://console.postgres.ai/gitlab/gitlab-production-main/sessions/29050/commands/90509

An example update query

UPDATE
    vulnerability_reads
SET
    traversal_ids = namespaces.traversal_ids
FROM
    namespaces
WHERE
    vulnerability_reads.vulnerability_id IN (100000, 100001, 100002, 100003, 100004, 100005, 100006, 100007, 100008, 100009, 100010, 100011, 100012, 100013, 100014, 100015, 100016, 100017, 100018, 100019, 100020, 100021, 100022, 100023, 100024, 100025, 100026, 100027, 100028, 100029, 100030, 100031, 100032, 100033, 100034, 100035, 100036, 100037, 100038, 100039, 100040, 100041, 100042, 100043, 100044, 100045, 100046, 100047, 100048, 100049)
    AND namespaces.id = vulnerability_reads.namespace_id

https://console.postgres.ai/gitlab/gitlab-production-main/sessions/29050/commands/90508