[libovsdb] Run libovsdb modelgen on latest OVN NB schema

[alexanderConstantinescu]

This commit bumps libovsdb's model to a more recent OVN NB DB schema version which contains elements such as LogicalRouterPolicy.Nexthops and such.

/assign @jcaamano

- What this PR does and why is it needed

- Special notes for reviewers

- How to verify it

- Description for the changelog

[jcaamano]

/lgtm

@dave-tucker wan't there a fix for modelgen that didn't generate arrays for min:0 max:1 properties?

[dave-tucker]

@jcaamano yes but it's still waiting review ovn-org/libovsdb#204

[jcaamano]

I will give it a shot but I guess @amorenoz needs to look at it as well.

/lgtm

[alexanderConstantinescu]

/retest

[coveralls]

Coverage increased (+0.06%) to 53.252% when pulling a54665f on alexanderConstantinescu:bump-modelgen into 676cf92 on ovn-org:master.

[alexanderConstantinescu]

External GW e2e tests seem to be one fire:

https://github.com/ovn-org/ovn-kubernetes/pull/2373/checks?check_run_id=3193448320

Summarizing 3 Failures:

[Fail] BFD e2e non-vxlan external gateway through a gateway pod Should validate TCP/UDP connectivity to an external gateway's loopback address via a pod with external gateway annotations enabled [It] TCP ipv6 
/home/runner/work/ovn-kubernetes/ovn-kubernetes/test/e2e/external_gateways.go:982

[Fail] BFD e2e multiple external gateway validation Should validate TCP/UDP connectivity to multiple external gateways for a UDP / TCP scenario [It] IPV6 udp 
/home/runner/work/ovn-kubernetes/ovn-kubernetes/test/e2e/external_gateways.go:788

[Fail] BFD e2e multiple external gateway validation Should validate TCP/UDP connectivity to multiple external gateways for a UDP / TCP scenario [It] IPV6 udp 
/home/runner/work/ovn-kubernetes/ovn-kubernetes/test/e2e/external_gateways.go:788

https://github.com/ovn-org/ovn-kubernetes/pull/2373/checks?check_run_id=3193448419

Summarizing 2 Failures:

[Fail] BFD e2e non-vxlan external gateway through a gateway pod Should validate TCP/UDP connectivity to an external gateway's loopback address via a pod with external gateway annotations enabled [It] UDP ipv6 
/home/runner/work/ovn-kubernetes/ovn-kubernetes/test/e2e/external_gateways.go:572

[Fail] BFD e2e non-vxlan external gateway through a gateway pod Should validate TCP/UDP connectivity to an external gateway's loopback address via a pod with external gateway annotations enabled [It] UDP ipv6 
/home/runner/work/ovn-kubernetes/ovn-kubernetes/test/e2e/external_gateways.go:572

No relation to this though, so I am merging