Do not filter IP addresses by VRF as default

By default, we don't filter IP address information from Netbox by VRF.

Previously, we used `None` as the default for `vrf_id` to avoid this filtering.
However, from pynetbox v7.4.0, `None` will be replaced by `'null'`.
Using `'null'` will only retrieve addresses that do not have a VRF configured, so the default behavior has changed unintentionally.

This commit will remove `vrf_id` from the query parameter by default.

octodns_netbox/__init__.py

@@ -158,14 +158,22 @@ def _populate_PTR(self, zone: Zone, family: Literal[4, 6]) -> typing.List[Rr]:
         ret = []
         network = octodns_netbox.reversename.to_network(zone)
 
-        kw = {f"{self.field_name}__empty": "false"}
-        ipam_records = self._nb_client.ipam.ip_addresses.filter(
-            parent=network.compressed,
-            family=family,
-            vrf_id=self.populate_vrf_id,
-            tag=self.populate_tags,
-            **kw,
-        )
+        kw = {
+            f"{self.field_name}__empty": "false",
+            "parent": network.compressed,
+            "family": family,
+            "vrf_id": self.populate_vrf_id,
+            "tag": self.populate_tags,
+        }
+
+        # https://github.com/netbox-community/pynetbox/pull/545
+        # From pynetbox v7.4.0, None will be mapped to null.
+        # When vrf_id is null, it does not mean that it is not filtered by vrf_id,
+        # but it would be an intention that VRF is not set.
+        if kw["vrf_id"] is None:
+            kw.remove("vrf_id")
+
+        ipam_records = self._nb_client.ipam.ip_addresses.filter(**kw)
 
         for ipam_record in ipam_records:
             ip_address = ip_interface(ipam_record.address).ip
@@ -188,10 +196,20 @@ def _populate_PTR(self, zone: Zone, family: Literal[4, 6]) -> typing.List[Rr]:
     def _populate_normal(self, zone: Zone) -> typing.List[Rr]:
         ret = []
 
-        kw = {f"{self.field_name}__ic": zone.name[:-1]}
-        ipam_records = self._nb_client.ipam.ip_addresses.filter(
-            vrf_id=self.populate_vrf_id, tag=self.populate_tags, **kw
-        )
+        kw = {
+            f"{self.field_name}__ic": zone.name[:-1],
+            "vrf_id": self.populate_vrf_id,
+            "tag": self.populate_tags,
+        }
+
+        # https://github.com/netbox-community/pynetbox/pull/545
+        # From pynetbox v7.4.0, None will be mapped to null.
+        # When vrf_id is null, it does not mean that it is not filtered by vrf_id,
+        # but it would be an intention that VRF is not set.
+        if kw["vrf_id"] is None:
+            kw.remove("vrf_id")
+
+        ipam_records = self._nb_client.ipam.ip_addresses.filter(**kw)
 
         for ipam_record in ipam_records:
             ip_address = ip_interface(ipam_record.address).ip