Remove forcing disabled cgos Darwin

[joshbranham]

Unsure if this is the right approach but wanted to get some others input. I often run into issues on macOS where I cannot run kops validate cluster due to failed DNS resolution. I am using OpenVPN Connect which does not edit /etc/resolv.conf (which is not standard anymore in macOS anyways at least). By forcing cgos to be disabled, kops validate cluster uses the net packages default resolver that only uses the nameserver listed in /etc/resolv.conf. In this case, that is the DHCP DNS, which fails.

To see the DNS difference, you can see the single nameserver listed in /etc/resolv.conf and then other resolvers which are populated via my VPN client.

(⎈ |kube-development-01.<redacted>)[kops] cat /etc/resolv.conf                                                                                                                                        remove-disabling-darwin-cgos  ✱
#
# macOS Notice
#
# This file is not consulted for DNS hostname resolution, address
# resolution, or the DNS query routing mechanism used by most
# processes on this system.
#
# To view the DNS configuration used by this system, use:
#   scutil --dns
#
# SEE ALSO
#   dns-sd(1), scutil(8)
#
# This file is automatically generated.
#
nameserver 10.0.1.1

(⎈ |kube-development-01.<redacted>)[kops] scutil --dns                                                                                                                                                   remove-disabling-darwin-cgos  ✱
DNS configuration

resolver #1
  nameserver[0] : 10.0.1.1
  if_index : 8 (en0)
  flags    : Request A records
  reach    : 0x00020002 (Reachable,Directly Reachable Address)

resolver #2
  domain   : ops.<redacted>.com
  nameserver[0] : 172.27.0.2
  flags    : Supplemental, Request A records
  reach    : 0x00000002 (Reachable)
  order    : 101000

resolver #3
  domain   : services.<redacted>.com
  nameserver[0] : 172.27.0.2
  flags    : Supplemental, Request A records
  reach    : 0x00000002 (Reachable)
  order    : 101001

The PR that added this functionality was from a few years ago, and it seems all tests still pass and it did resolve my issue. Curious on others thoughts here. Links below for more detail:

PR adding it: #3709
Kubernetes/kubernetes PR for building on darwin for darwin_ to use cgos: kubernetes/kubernetes#64219

[joshbranham]

cc @chrislovecnm regarding this commit, any thoughts on how to validate if your change is still needed (short of the normal test suite passing.)

c7ef856#diff-b0ce76c214af36d89279c38161d1d727

[johngmyers]

/test pull-kops-verify-staticcheck

[justinsb]

I fired up a mac and wasn't able to reproduce the issues that motivated this a few years ago - I think it's reasonable to assume they are fixed by now (but we should be careful about cherry-picking this back so that we have plenty of time to see if there are still lingering bugs)

Thanks for tracking down the problem and fixing @joshbranham

/approve
/lgtm

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: joshbranham, justinsb

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[johngmyers]

/test pull-kops-e2e-kubernetes-aws

[johngmyers]

/test pull-kops-e2e-kubernetes-aws