let's wait until #42249 is merged, otherwise vendor check on master will fail (when it's merged, I'll revendor so that the dependency will be removed)

#42249 is merged so @thaJeztah this is ready to be rebased

Arf.. looks like BuildKit also still uses it, so looks like I need to open a PR there to replace it;

A bit odd though that we're importing from a cmd feels like some more refactoring there would be good.

Anyway; rebased; 🤞 hopefully not hitting a flaky test this time

Arm64 failing on the flaky libnetwork test; #42459

=== RUN   TestNetworkDBIslands
networkdb_test.go:864: timeout hit after 2m0s: node5:Waiting for all nodes to cleanly leave, left: 2, failed nodes: 1

Windows now failing on the same test 😞. Kicking CI again

Failure (again) on arm64: TestConcurrencyNoWait tracked through #42458

=== Failed
 === FAIL: libnetwork/iptables TestConcurrencyNoWait (0.10s)
     iptables_test.go:217:  (iptables failed: iptables -t nat -A POSTROUTING -p tcp -s 172.17.0.1 -d 172.17.0.1 --dport 4321 -j MASQUERADE: Another app is currently holding the xtables lock. Perhaps you want to use the -w option?
          (exit status 4))

This is gonna be playing "whack-a-mole"; if other platforms pass, I'll merge, as we'd have had a green run for all jobs (in different combinations), and they should be unrelated anyway

Everything else is green; bringing this one in