Add ipv6 localhost to /etc/hosts on ipv6 nodes

[adobley]

What this PR does / why we need it

We removed a workaround for containerd in #3765

Containerd expects localhost to point to 127.0.0.1 and to ::1 for port forwarding support. This change will add ::1 localhost to the hosts file when the node is IPv6.

Describe testing done for PR

We created a cluster using clusterclass on vSphere and saw that our change was applied correctly.

We are running networking sonobuoy tests on that cluster now.

Release note

On IPv6 nodes localhost will resolve to ::1

Additional information

Special notes for your reviewer

[adobley]

/test install-vc7

[github-actions]

Cluster Generation A/B Results:
https://storage.googleapis.com/tkg-clustergen/3883/20221109200339/clustergen.diff.txt
Author/reviewers:
Please review to verify that the effects on the generated cluster configurations are exactly what the PR intended, and give a thumbs-up if so.

[alfredthenarwhal]

@adobley: /test install-vc7
Commit: 289fa12

Build failed! Build no: 3177

[adobley]

/test install-vc7

[github-actions]

Cluster Generation A/B Results:
https://storage.googleapis.com/tkg-clustergen/3883/20221110005638/clustergen.diff.txt
Author/reviewers:
Please review to verify that the effects on the generated cluster configurations are exactly what the PR intended, and give a thumbs-up if so.

[adobley]

/test install-vc7

[github-actions]

Cluster Generation A/B Results:
https://storage.googleapis.com/tkg-clustergen/3883/20221110011200/clustergen.diff.txt
Author/reviewers:
Please review to verify that the effects on the generated cluster configurations are exactly what the PR intended, and give a thumbs-up if so.

[github-actions]

Cluster Generation A/B Results:
https://storage.googleapis.com/tkg-clustergen/3883/20221110175933/clustergen.diff.txt
Author/reviewers:
Please review to verify that the effects on the generated cluster configurations are exactly what the PR intended, and give a thumbs-up if so.

[codecov]

Codecov Report

Merging #3883 (187d47a) into main (1ab6021) will decrease coverage by 0.89%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main    #3883      +/-   ##
==========================================
- Coverage   46.97%   46.08%   -0.90%     
==========================================
  Files         402      427      +25     
  Lines       40203    41754    +1551     
==========================================
+ Hits        18887    19241     +354     
- Misses      19569    20750    +1181     
- Partials     1747     1763      +16     

Impacted Files	Coverage Δ
...ons/controllers/packageinstallstatus_controller.go	79.15% <0.00%> (ø)
cmd/cli/plugin/cluster/set_machinehealthcheck.go	23.33% <0.00%> (ø)
cmd/cli/plugin/cluster/available_upgrade.go	16.32% <0.00%> (ø)
cmd/cli/plugin/cluster/get.go	6.27% <0.00%> (ø)
cmd/cli/plugin/cluster/list.go	11.36% <0.00%> (ø)
.../cli/plugin/cluster/set_machinehealthcheck_node.go	23.33% <0.00%> (ø)
cmd/cli/plugin/cluster/main.go	0.00% <0.00%> (ø)
...cluster/delete_machinehealthcheck_control_plane.go	16.66% <0.00%> (ø)
cmd/cli/plugin/cluster/set_node_pool.go	14.63% <0.00%> (ø)
...md/cli/plugin/cluster/delete_machinehealthcheck.go	19.23% <0.00%> (ø)
... and 19 more

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[adobley]

/test install-vc7

[adobley]

/test install-vc7

[alfredthenarwhal]

@adobley: /test install-vc7
Commit: 187d47a

Build failed! Build no: 3184

[vuil]

looks like the clustergen tests for vsphere configs are broken due to d124a45
cc @hongtaiwang
Would have been nice to also see the clustergen diffs due to this change.

Changes lgtm.