Neutron OVN Metadata agent fails on kolla redeploy/reconfigure with podman

[Caleb Sjostedt]

When running OVN using podman as the container engine, the metadata service will fail to bind to netns on compute nodes running the metadata service after a kolla deploy/reconfigure of neutron. This happens if the /var/run/netns directory is not empty.

How to reproduce:
1. Deploy openstack with podman as the container engine, ovn as the network, and ``neutron_ovn_distributed_fip`` turned on
2. After the initial deploy, run deploy/reconfigure again and the metadata service on compute nodes should stop responding.

Environment
OS: Ubuntu 22.04 LTS
Kernel: 5.15.0-92-generic
Podman version: 3.4.4
Kolla Ansible version: stable/2023.2
Image source: Official Kolla images

Relevant globals vars:
```globals.yml

neutron_plugin_agent: "ovn"
enable_neutron_dvr: "yes"
enable_neutron_agent_ha: "yes"
enable_neutron_provider_networks: "yes"
enable_neutron_trunk: "yes"
enable_neutron_port_forwarding: "yes"
enable_nova_ssh: "yes"

##############################
# Neutron - networking options
##############################
# Enable distributed floating ip for OVN deployments
neutron_ovn_distributed_fip: "yes"

# Enable DHCP agent(s) to use with OVN
neutron_ovn_dhcp_agent: "yes"
```

Podman container log:
```
Mar 05 06:03:28 compute-1c podman[1526183]: 2024-03-05 06:03:28.531860924 +0000 UTC m=+0.081029044 container exec 798503ec5e3d95875bce00881ed63ad1eea348bcf61601438a5c3815
4d16e1e0 (image=quay.io/openstack.kolla/neutron-metadata-agent:2023.2-ubuntu-jammy, name=neutron_ovn_metadata_agent, org.opencontainers.image.version=22.04, build-date=20
240227, kolla_version=17.2.1, maintainer=Kolla Project (https://launchpad.net/kolla), name=neutron-metadata-agent, org.opencontainers.image.ref.name=ubuntu)
Mar 05 06:03:28 compute-1c conmon[1526172]: ++ . /usr/local/bin/kolla_neutron_extend_start
Mar 05 06:03:28 compute-1c conmon[1526172]: + echo 'Running command: '\''neutron-ovn-metadata-agent --config-file /etc/neutron/neutron.conf --config-file /etc/neutron/neu
tron_ovn_metadata_agent.ini'\'''
Mar 05 06:03:28 compute-1c podman[1526118]: ++ . /usr/local/bin/kolla_neutron_extend_start
Mar 05 06:03:28 compute-1c podman[1526118]: + echo 'Running command: '\''neutron-ovn-metadata-agent --config-file /etc/neutron/neutron.conf --config-file /etc/neutron/neu
tron_ovn_metadata_agent.ini'\'''
Mar 05 06:03:28 compute-1c podman[1526118]: Running command: 'neutron-ovn-metadata-agent --config-file /etc/neutron/neutron.conf --config-file /etc/neutron/neutron_ovn_me
tadata_agent.ini'
Mar 05 06:03:28 compute-1c podman[1526118]: + exec neutron-ovn-metadata-agent --config-file /etc/neutron/neutron.conf --config-file /etc/neutron/neutron_ovn_metadata_agen
t.ini
Mar 05 06:03:28 compute-1c conmon[1526172]: Running command: 'neutron-ovn-metadata-agent --config-file /etc/neutron/neutron.conf --config-file /etc/neutron/neutron_ovn_me
tadata_agent.ini'
Mar 05 06:03:28 compute-1c conmon[1526172]: + exec neutron-ovn-metadata-agent --config-file /etc/neutron/neutron.conf --config-file /etc/neutron/neutron_ovn_metadata_agen
t.ini
Mar 05 06:03:28 compute-1c podman[1526183]: 2024-03-05 06:03:28.573008493 +0000 UTC m=+0.122176633 container exec_died 798503ec5e3d95875bce00881ed63ad1eea348bcf61601438a5
c38154d16e1e0 (image=quay.io/openstack.kolla/neutron-metadata-agent:2023.2-ubuntu-jammy, name=neutron_ovn_metadata_agent, execID=e9a37a8cb7c70562e905b715df87a343091cce911
14f190ef39226fc6f7e2bde)
Mar 05 06:03:28 compute-1c podman[1526183]: unhealthy
Mar 05 06:03:28 compute-1c systemd[1]: 798503ec5e3d95875bce00881ed63ad1eea348bcf61601438a5c38154d16e1e0.service: Main process exited, code=exited, status=1/FAILURE
Mar 05 06:03:28 compute-1c systemd[1]: 798503ec5e3d95875bce00881ed63ad1eea348bcf61601438a5c38154d16e1e0.service: Failed with result 'exit-code'.
```