Use dl.k8s.io instead of hardcoded GCS URIs

[spiffxp]

What this PR does / why we need it:

The only time a kubernetes GCS bucket name should be showing up in a
hardcoded URI is if gsutil is being used (e.g. gsutil cp gs://foo/bar .)

Otherwise, for tools like curl or wget, dl.k8s.io is much nicer for us
as a project, since we can transparently change where that redirects to
without having to change code everywhere

These changes will mean no changes will be necessary to accommodate a
gs://kubernetes-release -> gs://k8s-release migration equivalent of
the CI migration we're going through right now

These changes also address the gs://kubernetes-release-dev references
currently used by this repo (ref:
kubernetes/k8s.io#2318)

While I was here, I updated images/capi/hack/image-new-kube.py to run
with python3. I assumed this was OK since I saw sibling scripts using
python3

Which issue(s) this PR fixes (optional, in fixes #(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged): Fixes #

Additional context
This is similar to the PR I've opened for cluster-api: kubernetes-sigs/cluster-api#4958

[spiffxp]

/cc @CecileRobertMichon @sbueringer @randomvariable
Since I requested review from y'all on kubernetes-sigs/cluster-api#4958

[spiffxp]

/cc @cpanato
Since you've got some familiarity with this codebase and reviewed some of the other related PR's in this area

[cpanato]

/cc @cpanato
Since you've got some familiarity with this codebase and reviewed some of the other related PR's in this area

Will review, thanks for the heads up!

[sbueringer]

Change looks reasonable to me, but I'm not really familiar with the codebase

[CecileRobertMichon]

/retest

[cpanato]

dont see anything that hurt my eyes :)

/lgtm

[spiffxp]

/cc @hakman @rifelpet
for images/kube-deploy

[CecileRobertMichon]

blocked by OVA CI

/cc @codenrhoden

[rifelpet]

/lgtm for images/kube-deploy

[rifelpet]

/approve

[cpanato]

/test pull-ova-all

[cpanato]

saw this: vsphere: ServerFaultCode: Cannot complete login due to an incorrect user name or password.

will take a look at this job and config, I'm not familiar with vsphere

[cpanato]

being discussed here: https://kubernetes.slack.com/archives/C01E0Q35A8J/p1626725388053700

[codenrhoden]

/lgtm
The OVA job shouldn't be blocking anymore. Will be working to sort that out this week.

[CecileRobertMichon]

/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: CecileRobertMichon, rifelpet, spiffxp

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• images/capi/OWNERS [CecileRobertMichon]
• images/kube-deploy/OWNERS [CecileRobertMichon,rifelpet]

Approvers can indicate their approval by writing /approve in a comment
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[k8s-ci-robot]

@spiffxp: The following test failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Rerun command
pull-ova-all	db0f4fa	link	/test pull-ova-all

Full PR test history. Your PR dashboard. Please help us cut down on flakes by linking to an open issue when you hit one in your PR.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository. I understand the commands that are listed here.

[spiffxp]

/test pull-azure-vhds
since I think this was a flake
/override pull-ova-all
using my github admin superpowers

I'm honestly not sure why tide is paying attention to either of these if they're not marked as required in the UI

[spiffxp]

Not sure why https://prow.k8s.io/command-help#override didn't work, let's try https://prow.k8s.io/command-help#skip

/skip