since nodejs/node#14731 was landed, node can now finally resolve DNS the way the underlying OS is configured to do.
I suggest npm adapts this for its DNS queries.

What's going wrong?

When trying to use npm on an IPv6 only network, currently, npm (thanks to node's DNS lib) will prefer IPv4 addresses, even if it has no way to connect to such an address.

How can the CLI team reproduce the problem?

This is tricky…
Unless you have an IPv6 only VM anywhere around it's really non-trivial.
It's even trickier to get IPv6 addresses for domains that only have IPv4 addresses to begin with!
i.e.: You'd have to implement some form of DNS64 (and/or NAT64)

supporting information:

really, any… npm / nodejs / os.
IPv6 only is the important part.
This has been an issue (regression…) for a long, long time.