Golang net: new test TestIPv4WriteMsgUDPAddrPortTargetAddrIPVersion fails on plan9 [1.24 backport]

@millerresearch requested issue #75017 to be considered for backport to the next 1.24 minor release.

@gopherbot please consider this for backport to 1.24 and 1.25

CL 689976, which caused this issue by breaking the plan9 gotip builders, has been backported to 1.24 and 125. So the plan9 builders for those branches are now broken too.

Comment From: mrkfrmn

This seems reasonable to approve, as it's test-only.

Comment From: gopherbot

Change https://go.dev/cl/704279 mentions this issue: [release-branch.go1.24] net: skip TestIPv4WriteMsgUDPAddrPort on plan9

Comment From: gopherbot

Closed by merging CL 704279 (commit 6ab3a41c864978d98da4d1a1afd75975185a663b) to release-branch.go1.24.