Support primary_key in mirror tag

Rebased variant of #367

To: [email protected]
Cc: Stefan Kempf <[email protected]>
Signed-off-by: Thomas Weißschuh <[email protected]>

---
Changes in v2:
- EDITME: describe what is new in this series revision.
- EDITME: use bulletpoints and terse descriptions.
- Link to v1: https://lore.kernel.org/r/[email protected]



--- b4-submit-tracking ---
# This section is used internally by b4 prep for tracking purposes.
{
  "series": {
    "revision": 2,
    "change-id": "20241118-primary_key-e71b055eddf8",
    "prefixes": [],
    "history": {
      "v1": [
        "[email protected]"
      ]
    }
  }
}