fix: move kubectl image and tag ref to default cm

[kshitij-kumar-ngt]

What type of PR is this?
Remove the image ref (uri and tag) from chart's value.yaml and move them to helmRelease cm.yaml
Related PR: mesosphere/kommander-applications#4459

What this PR does/ why we need it:

Having the kubectl image and tag ref in chart breaks license job for 2.17.x since 2.17.x has kubectl v1.34.0 ref and this chart brings v1.35.1. Anyways this should always be in default cm.yaml and not in this chart copy

Which issue(s) this PR fixes:

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

Checklist

• If a chart is changed, the chart version is correctly incremented.
• The commit message explains the changes and why are needed.
• The code builds and passes lint/style checks locally.
• The relevant subset of integration tests pass locally.
• The core changes are covered by tests.
• The documentation is updated where needed.

[kshitij-kumar-ngt]

Do we need to bump the chart version for this minor change @takirala ?

[takirala]

Do we need to bump the chart version for this minor change @takirala ?

If we don't bump it, it would overwrite an artifact that we already shipped. If the chart version is not already shipped then perhaps we don't need to bump the version but otherwise we MUST bump the version.

[kshitij-kumar-ngt]

Understood thanks. Let me do it