This bug fix is currently targeted for rhos-19.0.0. Action item for the neutron team is to make sure that the mentioned upstream [2] patch is cherry picked to downstream 19.0-trunk-patches.
This cherry picked will have to be carefully thought out as it is bumping RPC version.

------------------ Original bug description ----------------------------------------------
Upstream bug: https://bugs.launchpad.net/networking-baremetal/+bug/2086640

This is a long standing bug upstream, we have customers asking for this to be fixed to avoid the need to manually clean up agents.

To facilitate for OSPRH-15081, the fix in networking-baremetal[1] depends-on Neutron's agent report_state RPC API to support an action to delete the agent. The change to add this support ha been proposed, see change[2] in upstream gerrit.

[1] https://review.opendev.org/c/openstack/networking-baremetal/+/945500
[2] https://review.opendev.org/c/openstack/neutron/+/945497