Remove host mgmt mac address from maintenance

[Eric MacDonald]

Brief Description
-----------------
Maintenance caching hosts management mac addresses and performing validation checks against the saved mgmt mac addresses is impacting hw node replacement.

Severity
--------
Minor: HW node replacement is impacted.

Steps to Reproduce
------------------
Replace a host or host's management NIC.

Expected Behavior
------------------
Node or NIC replacement succeeds.

Actual Behavior
----------------
Node or NIC replacement fails.

Reproducibility
---------------
100% reproducible if the management NIC mac address changes while the node is not deleted and readded.

System Configuration
--------------------
Any.

Branch/Pull Time/Commit
-----------------------
Any prior to this bug report.

Last Pass
---------
Unknown.

Test Activity
-------------
Node or NIC replacement.

Workaround
----------
Need to delete and readd node or restart mtcAgent after the node or NIC is replaced.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/c/starlingx/metal/+/910649

[OpenStack Infra (hudson-openstack)]

Change abandoned by "Eric MacDonald <email address hidden>" on branch: master
Review: https://review.opendev.org/c/starlingx/metal/+/910649
Reason: No longer needed