Mark the injection of the SSH agent postStart event as experimental feature

[vinokurig]

What does this PR do?

Wrap the AddSshAgentPostStartEvent function into the EnableExperimentalFeatures condition.

What issues does this PR fix or reference?

https://github.com/devfile/devworkspace-operator/issues/1337

Is it tested? How?

Create a workspace with a container without sh:

apiVersion: workspace.devfile.io/v1alpha2
kind: DevWorkspace
metadata:
  name: plain-devworkspace
spec:
  routingClass: che
  started: true
  template:
    components:
      - container:
          image: 'quay.io/devfile/universal-developer-image:ubi8-latest'
        name: universal-developer-image
      - container:
          image: 'ghcr.io/l0rd/outyet@sha256:3ab91b5801ab2e2a6147cab5d4a959838d9318921298e84cf7b6d19a3359e496'
        name: test

See: workspace starts successfully.

PR Checklist

• [ ] E2E tests pass (when PR is ready, comment /test v8-devworkspace-operator-e2e, v8-che-happy-path to trigger)
  • [ ] v8-devworkspace-operator-e2e: DevWorkspace e2e test
  • [ ] v8-che-happy-path: Happy path for verification integration with Che

[openshift-ci[bot]]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: vinokurig Once this PR has been reviewed and has the lgtm label, please assign dkwon17 for approval. For more information see the Kubernetes Code Review Process.

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Needs approval from an approver in each of these files: - **[OWNERS](https://github.com/devfile/devworkspace-operator/blob/main/OWNERS)** Approvers can indicate their approval by writing `/approve` in a comment Approvers can cancel approval by writing `/approve cancel` in a comment

[openshift-ci[bot]]

Hi @vinokurig. Thanks for your PR.

I'm waiting for a devfile member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

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[vinokurig]

@AObuchow sorry I did not see your pull request so I am closing mine in favour of yours.

[AObuchow]

@vinokurig No need to apologize, I appreciate you working on this :) Sounds good with me.