uni04delta-ipv6: No OVN DHCP for baremetal ports

Adds ovn/disable_ovn_dhcp_for_baremetal_ports
configuration to the uni04delta-ipv6 config_download.yaml
using `neutron::config::plugin_ml2_config`.

This disables OVN's built-in DHCP service for baremetal
ports, allowing external DHCP to be used instead. Uses the
config class approach since the direct puppet parameter was
not backported to OSP 17.1.

Jira: OSPRH-20021
Signed-off-by: Harald Jensås <hjensas@redhat.com>

Author: hjensas

scenarios/uni04delta-ipv6/config_download.yaml

@@ -47,6 +47,9 @@ parameter_defaults:
     nova::compute::libvirt::virt_type: qemu
   ExtraConfig:
     neutron::notification_driver: 'noop'
+    neutron::config::plugin_ml2_config:
+      ovn/disable_ovn_dhcp_for_baremetal_ports:
+        value: true
   BarbicanSimpleCryptoGlobalDefault: true
   Debug: true
   DockerPuppetDebug: true