Mac address can not be unset via API

[amhn]

NetBox version

v3.5.0

Python version

3.11

Steps to Reproduce

1. Create VM Interface with mac address set
2. Try removing the mac address with null:

curl \
-H "Authorization: Token $NETBOX_TOKEN" \
-H "Content-type: application/json" \
$NETBOX_SCHEME://$NETBOX_URL/api/virtualization/interfaces/4/ \
-X PATCH \
--data '{"mac_address": null}'

3. Try removing the mac address with empty string:

curl \
-H "Authorization: Token $NETBOX_TOKEN" \
-H "Content-type: application/json" \
$NETBOX_SCHEME://$NETBOX_URL/api/virtualization/interfaces/4/ \
-X PATCH \
--data '{"mac_address": ""}'

Expected Behavior

Mac address can be set back to NULL via API

Observed Behavior

With step 2 the error message is {"mac_address":["This field may not be null."]}. With step 3 it is {"mac_address":["This field may not be blank."]}

Probably allow_null = True should be added to the mac_address field of the VMInterfaceSerializer (and InterfaceSerializer for device interfaces)