tests: Temporarily skip two testcases

The changes [1] and [2] made to CURRENT introduce races between ifnet
detach and vmove operations. That requires extra effort to fix. They
are not MFCed to stable branches so the latter are not affected.
Temporarily skip two affected tests on CURRENT right now.

[1] 0bf42a0a05b9 bpf: virtualize bpf_iflist
[2] a4d766caf711 bpf: add a crutch to support if_vmove

PR: 292993
Discussed with: kp