Update summon-sidecar E2E test to use namespace-label authn-k8s

[john-odonnell]

Desired Outcome

Update our end-to-end test workflow to validate Authn-K8s namespace label selector restriction.

Implemented Changes

• Update Cluster Prep Helm chart ClusterRole to provide get permission on namespaces.
• The test-app-summon-sidecar host is configured with the namespace-label-selector resource restriction. If the summon-sidecar app succeeds, then namespace label-based Authn-K8s is functional.

Connected Issue/Story

N/A

Definition of Done

At least 1 todo must be completed in the sections below for the PR to be
merged.

Changelog

• The CHANGELOG has been updated, or
• This PR does not include user-facing changes and doesn't require a
  CHANGELOG update

Test coverage

• This PR includes new unit and integration tests to go with the code
  changes, or
• The changes in this PR do not require tests

Documentation

• Docs (e.g. READMEs) were updated in this PR
• A follow-up issue to update official docs has been filed here: insert issue ID
• This PR does not require updating any documentation

Behavior

• This PR changes product behavior and has been reviewed by a PO, or
• These changes are part of a larger initiative that will be reviewed later, or
• No behavior was changed with this PR

Security

• Security architect has reviewed the changes in this PR,
• These changes are part of a larger initiative with a separate security review, or
• There are no security aspects to these changes

[rpothier]

Looks good! just one minor comment.

[rpothier]

Need the link to [0.23.8] defined at the bottom

[john-odonnell]

Thanks, updated.

[juniortaeza]

LGTM. We tested the functionality of this as well and it looks great. Thank you!

[juniortaeza]

LGTM!