Drop localhost to support crane registry serve in a container

[mattmoor]

This allows you to run docker run -e PORT=1234 --name foo.local cgr.dev/chainguard/crane registry serve and then --link foo.local to push to foo.local:1234.

Right now it only listens on the loopback interface, so unless it's run in a K8s-style pod with something that exposes and proxies things (e.g. like Knative / Cloud Run), it is inaccessible.

[codecov-commenter]

Codecov Report

Merging #1746 (8f30f61) into main (fe268b7) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main    #1746   +/-   ##
=======================================
  Coverage   71.93%   71.93%           
=======================================
  Files         122      122           
  Lines        9827     9827           
=======================================
  Hits         7069     7069           
  Misses       2077     2077           
  Partials      681      681           

[ewhauser]

@mattmoor - this causes network error warnings on MacOS:

Bazel's rules_oci makes use of crane so you end up with a warning for every image you are building which is untenable.