T6619: Remove the remaining uses of per-protocol FRR configs (backport #3916)

[mergify]

Change Summary

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Code style update (formatting, renaming)
• Refactoring (no functional changes)
• Migration from an old Vyatta component to vyos-1x, please link to related PR inside obsoleted component
• Other (please describe):

Related Task(s)

• https://vyos.dev/T6619
• https://vyos.dev/T6623

Related PR(s)

Component(s) name

Proposed changes

How to test

conf
set protocols static multicast route 224.202.0.0/24 next-hop 224.203.0.1
set protocols static multicast interface-route 224.203.0.0/24 next-hop-interface eth0 
commit
vtysh -c 'show running-config'

Smoketest result

vyos@vyos:~$ python3 /usr/libexec/vyos/tests/smoke/cli/test_protocols_static_multicast.py 
test_01_static_multicast (__main__.TestProtocolsStaticMulticast.test_01_static_multicast) ... ok

----------------------------------------------------------------------
Ran 1 test in 6.213s

OK

Checklist:

• I have read the CONTRIBUTING document
• I have linked this PR to one or more Phabricator Task(s)
• I have run the components SMOKETESTS if applicable
• My commit headlines contain a valid Task id
• My change requires a change to the documentation
• I have updated the documentation accordingly

---

This is an automatic backport of pull request #3916 done by [Mergify](https://mergify.com).

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