fix: delete static route should consider dualstack

[oilbeater]

Fix bug found in qos e2e failure

I1206 04:12:59.519482      13 pod.go:787] update pod kube-system/coredns-6d4b75cb6d-2f4hg
W1206 04:12:59.525818      13 ovn-nbctl-legacy.go:52] ovn-nbctl command error: ovn-nbctl --timeout=60 --no-wait --if-exists lr-route-del ovn-cluster 10.16.0.6,fd00:10:16::6 in 10ms
E1206 04:12:59.526008      13 pod.go:401] error syncing 'kube-system/coredns-6d4b75cb6d-5r6b8': ovn-nbctl: bad prefix argument: 10.16.0.6,fd00:10:16::6
, "exit status 1", requeuing
W1206 04:12:59.530624      13 ovn-nbctl-legacy.go:52] ovn-nbctl command error: ovn-nbctl --timeout=60 --no-wait --if-exists lr-route-del ovn-cluster 10.16.0.11,fd00:10:16::b in 8ms
E1206 04:12:59.530757      13 pod.go:401] error syncing 'qos/update-netem-qos': ovn-nbctl: bad prefix argument: 10.16.0.11,fd00:10:16::b
, "exit status 1", requeuing
W1206 04:12:59.533704      13 ovn-nbctl-legacy.go:52] ovn-nbctl command error: ovn-nbctl --timeout=60 --no-wait --if-exists lr-route-del ovn-cluster 10.16.0.7,fd00:10:16::7 in 9ms
E1206 04:12:59.533842      13 pod.go:401] error syncing 'kube-system/coredns-6d4b75cb6d-2f4hg': ovn-nbctl: bad prefix argument: 10.16.0.7,fd00:10:16::7

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What type of this PR

Examples of user facing changes:

• Bug fixes

Which issue(s) this PR fixes:

Fixes #(issue-number)