ci: switch from kubeval to kubeconform

[wyardley]

What this PR does / why we need it:

• Switch from kubeval, which is unmaintained and outdated, to kubeconform
• Update kubernetes versions in test matrices
• Use upstream schema for CRDs, so we don't have to ignore missing schemas in validation
• Switch away from deprecated output format
  https://github.blog/changelog/2022-10-11-github-actions-deprecating-save-state-and-set-output-commands/
• Switch CI nodeSelector examples to use disktype: ssd to avoid creating duplicates with baked in os defaults

Screenshot from local example:

Which issue this PR fixes

(optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close that issue when PR gets merged)

• fixes Consider using alternative source for kubeval schemas #360
• fixes Duplicate nodeSelector values in datadog chart with CI defaults #1312

Special notes for your reviewer:

Note: I don't know if any chart changes are triggered. I tested this locally, but may be good to do some additional testing in CI if you'd like.

CI changes only; let me know if you want me to bump version / changelog, though I imagine not relevant here.

I'm happy to remove v1.18.20 or add / remove other versions from the matrices - just let me know.

Checklist

[Place an '[x]' (no spaces) in all applicable fields. Please remove unrelated fields.]

• Chart Version bumped
• CHANGELOG.md has been updated

[wyardley]

Note: I just updated it to resolve a deprecation warning with set-output - once the job is approved, I will double-check that it looks correct

And, as mentioned before, I can bump the chart version if / when you all want, which is one of the test failures.

I don't think the go test failure is related to my changes?

[wyardley]

There is a separate (and similar) matrix of Kube versions for the go integration tests, which I'm happy to edit there / make standard with he ones in this PR if it helps (though I haven't yet)

[wyardley]

@clamoriniere would you be able to get someone to review / comment on this, and / or is there anything you'd like me to do / update?

[loutPhilipps]

It looks like there's an issue with the output format:

Error: Unable to process file command 'output' successfully.
Error: Invalid format 'charts/datadog-operator'

[wyardley]

It looks like there's an issue with the output format:

Ah! probably shouldn't have tried to fix this error at the same time.
https://stackoverflow.com/questions/74137120/how-to-fix-or-avoid-error-unable-to-process-file-command-output-successfully

I think it should have been changed anyway vs {changed}; not sure if just changing {changed}= to changed= will be sufficient, but I can just add in the solution using a heredoc and we can see if that works...

[wyardley]

@loutPhilipps if you want to trigger again, we can see if my output fixes now work.

[wyardley]

note: https://github.com/instrumenta/kubernetes-json-schema doesn't seem to have 1.16.15; 1.16.4 is the latest. Presumably this is Good Enough, but if someone can find the right schema version (I'm surprised kubeval worked with this) online in the right format, I can update the secondary schema location 🤷

[wyardley]

I rebased locally and slightly tweaked the wording, since there were conflicts from something merged after the previous version bump. Sorry for squashing your changes @clamoriniere

[wyardley]

Seems like it wanted additional bumps?
I bumped charts/datadog-crds and charts/datadog-operator too, in a separate commit, but let me know if you want me to revert it to how it was.

[clamoriniere]

Hi @wyardley
thanks again for all your work on this PR. Our CI is finally green ! 🥳
We will be able to merge it

[wyardley]

Thanks all!