Remove ignore_column rule for group_id from ScimOauthAccessToken

Series

group_id has been dead since group SCIM tokens moved to group_scim_auth_access_tokens in 17.9.

Prerequisites — target master, any order, all must land before step 2:

MR	What
!261148	GroupScimAuthAccessToken gets its own serializer
!261149	Real group_id only on the group SCIM API entity
!261150 (merged)	No SCIM token transfer on group org transfer

Steps — sequential, one milestone apart, since each needs the previous deployed, not just merged:

Step	MR	Milestone	What	State
1	!256720 (merged)	19.5	Delete orphaned group-level rows	merged
2	!256721	19.6	Remove code references, add ignore_column	open
3	!256722	19.7	Drop group_id column	open
4	!256725 👈	19.8	Remove ignore_column rule	open

What does this MR do and why?

Final cleanup. With the column dropped in !256722, the ignore_column :group_id rule on ScimOauthAccessToken is no longer needed, so it and the IgnorableColumns include are removed, along with the regression spec !256721 added to guard the rule.

!256721 annotated the rule with remove_with: '19.8', which is why this lands in 19.8.

References

• Tracking work item: #630160
• Sharding key audit: #624518

How to set up and validate locally

Requires !256722 to have been migrated, so the column is already gone.

ScimOauthAccessToken.ignored_columns.include?('group_id')  # => false

org = Organizations::Organization.first
token = ScimOauthAccessToken.create!(organization: org)
ScimOauthAccessToken.instance_token_for(token.token) == token  # => true
ScimOauthAccessToken.find_for_instance == token                # => true

Load Admin > Settings > General (instance SCIM token section) and a group's SAML/SCIM settings page to confirm both still render.

MR acceptance checklist

Evaluate this MR against the MR acceptance checklist.