Tentative ColdFront changes for 2025-06 maintenance

[QuanMPhm]

This is a list of tentative changes we're planning to introduce to Coldfront during the 2025-05-12 maintenance:

• Allow pushing user-allocation membership to Keycloak #249
• Allow using validate_allocations to validate Keycloak group memberships #307
• Add GPU quota to default quotas registration #295

[joachimweyl]

@knikolla & @QuanMPhm do we have confirmation this will be included?

[QuanMPhm]

Pushing out to next month, as other tasks has taken priority