Description of problem:

In attempt to fix Repair API https://bugzilla.redhat.com/show_bug.cgi?id=2173671, we broke pulp-to-pulp sync aka SatServer→Capsule sync.

Capsule docker sync fails with `pulp [321cbe02e8f6495b8c21d50dece4ceee]: pulpcore.tasking.tasks:INFO: Task d018de7a-b7e3-4a1c-b028-0caa260e05dd failed (406, message='Not Acceptable', url=URL('https://ark.stackhpc.com/v2/stackhpc/centos-source-skydive-analyzer/tags/list'))`

Version-Release number of selected component (if applicable):
starting with pulp-container-2.14.6-1, pulp-container-2.15.1-1

How reproducible:

Steps to Reproduce:
1. Trigger a capsule sync
2.
3.

Actual results:
sync succeeds

Expected results:
sync fails with 406

Additional info: