fix: match interfaces by the primary MAC address object on NetBox >= 4.2

[tfoks]

On NetBox >= 4.2, map_object_interfaces_to_current_interfaces() now matches interfaces by the MAC address of their primary_mac_address object. Before, it used the legacy mac_address field. That field keeps the value NetBox returned at read time and isn't updated during a run, so a source could match against a MAC address that an earlier source had already replaced. NetBox < 4.2 keeps using mac_address.

With a VMware and a check_redfish source syncing the same ESXi hosts, this merged the Lenovo XCC port into vmk0 on every run, which moved the XCC IP to vmk0 and unset the device's primary IP. Details in #584.

Changes:

• module/sources/common/source_base.py: read the MAC address from the primary MAC address object on NetBox >= 4.2
• tests/test_interface_matching_primary_mac.py: a stale legacy MAC no longer matches, and the primary MAC still does. Both tests fail without the fix.

Tested against NetBox 4.7.2 with a vCenter 8.0.3 source and the check_redfish inventory files of HPE and Lenovo hosts: the XCC ports get their own interfaces again, vmk0 keeps its MAC and management IP, and a second run makes no changes. pytest: 259 passed (vcsim installed).

Fixes #584

🤖 Generated with Claude Code

[semx]

Reproduced on a NetBox 4.7.2 with vcsim and a check_redfish inventory for the same host, the BMC MAC planted on vmk0 as its primary MAC the way an earlier run leaves it. Without this change the BMC port is merged into vmk0 on every run: vmk0 becomes mgmt_only, gets the BMC IP, loses the host IP and the device loses primary_ip4; the next run flips it back. With it, vmk0 gets its own MAC back, the BMC port gets its own interface with its IP, primary_ip4 stays, and the second run changes nothing. Both new tests fail on development without the fix; the suite is green with it.

Two things, neither blocks:

• The < 4.2 branch has no test: dropping the version check and always reading the primary MAC object passes the whole suite. One case with inventory.netbox_api_version = "4.1.0" and an interface that only has mac_address would pin it. Fine to add in a follow-up if you prefer.
• get_object_based_on_macs() in the VMware source still identifies hosts and VMs by the legacy mac_address. Same staleness, different place; I'll track it separately, it is not part of this fix.

Branch is off main again; I'll switch the base to development and merge once CI has run.