[DEPR-2U] Use-Jwt-Cookie header

[timmc-edx]

2U followup ticket for:

• [DEPR]: USE-JWT-COOKIE header openedx/edx-drf-extensions#371

Note that the DEPR ticket above includes searches through the edx and openedx orgs. However, I don't want to list these individual PRs on the main DEPR.

Adding edx org PRs here as they arise:

• https://github.com/edx/edx-internal/pull/11469
• https://github.com/edx/edge-internal/pull/765
• https://github.com/edx/sandbox-internal/pull/355
• https://github.com/edx/subscriptions/pull/210
• https://github.com/edx/translatable-xblocks/pull/26
• Add comments for Jinja updates for USE-JWT
  • Single affected repo: docs: add comment for USE-JWT-COOKIE header configuration#67
• To be continued based on updated DEPR plan and searches...

IMPORTANT: The following PRs were reverted due to a problem during rollout. See the DEPR for an updated rollout plan.

Reverted/Closed PRs:

• feat: DEPR USE-JWT-COOKIE header edx-exams#312 (reverted)
• https://github.com/edx/subscriptions/pull/210 (reverted)
• https://github.com/edx/ai-translations/pull/207 (reverted)
• https://github.com/edx/financial-assistance/pull/63 (temporarily closed)

[robrap]

See the actual DEPR for details. The long-tail work on this may be expensive, without lots of benefit. Are there any parts that can be completed? Giving this a P5 for now. If we don't move forward, we may need to move the DEPR to a different status.