Neutron Extensions in kolla-ansible documentation out-of-date

[Smee Mcgee]

- [x] This doc is inaccurate in this way:
The Verification steps are inaccurate and have not been updated with changes made to the container configuration.
and running.

"On the network node(s), the neutron_vpnaas_agent should be up (image naming and versioning may differ depending on deploy configuration):"

"docker ps --filter name=neutron_vpnaas_agent"

The vpnaas_agent no longer exists as per release notes:
https://opendev.org/openstack/kolla-ansible/src/commit/46c2b60d9f58c8398929cbf2a4a935150817d601/releasenotes/notes/merge-neutron-vpnaas-role-with-neutron-l3-agent-90b91725344dda76.yaml

I dont have a fix to the document as I am new to kolla, and was attempting to configure vpnaas and now am stuck at the verification step.

** Environment **
OS: Rocky Linux 9.3 (Blue Onyx)
Kernel: Linux stack 5.14.0-362.8.1.el9_3.x86_64 #1 SMP PREEMPT_DYNAMIC Wed Nov 8 17:36:32 UTC 2023 x86_64 x86_64 x86_64 GNU/Linux
Docker Version: 26.0.1
Kolla-ansible version: 17.1.0