Fix is-multi-ns flag for triggerGroups

[seternate]

Changes

Fix that the --is-multi-ns flag on the eventlistener is set to true, when using a namespaceSelector on any triggerGroup.

Fixes https://github.com/tektoncd/triggers/issues/1652 Fixes https://github.com/tektoncd/triggers/issues/1617 Fixes https://github.com/tektoncd/triggers/issues/1700

Submitter Checklist

As the author of this PR, please check off the items in this checklist:

• [x] Has Docs if any changes are user facing, including updates to minimum requirements e.g. Kubernetes version bumps
• [x] Has Tests included if any functionality added or changed
• [x] Follows the commit message standard
• [x] Meets the Tekton contributor standards (including functionality, content, code)
• [x] Has a kind label. You can add one by adding a comment on this PR that contains /kind <type>. Valid types are bug, cleanup, design, documentation, feature, flake, misc, question, tep
• [x] Release notes block below has been updated with any user facing changes (API changes, bug fixes, changes requiring upgrade notices or deprecation warnings). See some examples of good release notes.
• [x] Release notes contains the string "action required" if the change requires additional action from users switching to the new release

Release Notes

Fix that the --is-multi-ns flag on the eventlistener is set to true, when using a namespaceSelector on any triggerGroup.

[seternate]

/kind bug

[tekton-robot]

Hi @seternate. Thanks for your PR.

I'm waiting for a tektoncd 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.

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[khrm]

We can ignore above tests failure. That's fixed by other PR.

[khrm]

/test pull-tekton-triggers-build-tests

[tekton-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: khrm, savitaashture

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Needs approval from an approver in each of these files: - ~~[OWNERS](https://github.com/tektoncd/triggers/blob/main/OWNERS)~~ [khrm,savitaashture] Approvers can indicate their approval by writing `/approve` in a comment Approvers can cancel approval by writing `/approve cancel` in a comment

[khrm]

/lgtm