Add OIDC Authentication feature flag

[karthikmurali60]

Fixes #7174

Proposed Changes

• 🎁 Add OIDC Authentication flag

Pre-review Checklist

• At least 80% unit test coverage
• E2E tests for any new behavior
• Docs PR for any user-facing impact
• Spec PR for any new API feature
• Conformance test for any change to the spec

Release Note

Docs

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: karthikmurali60 / name: Karthik Muraliprasad (befc053)

[knative-prow]

Welcome @karthikmurali60! It looks like this is your first PR to knative/eventing 🎉

[knative-prow]

Hi @karthikmurali60. Thanks for your PR.

I'm waiting for a knative 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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[creydr]

/ok-to-test

[codecov]

Codecov Report

Patch coverage has no change and project coverage change: +0.01% 🎉

Comparison is base (29ac3ee) 77.93% compared to head (befc053) 77.95%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #7183      +/-   ##
==========================================
+ Coverage   77.93%   77.95%   +0.01%     
==========================================
  Files         246      246              
  Lines       13200    13202       +2     
==========================================
+ Hits        10288    10291       +3     
  Misses       2390     2390              
+ Partials      522      521       -1     

Files Changed	Coverage Δ
pkg/apis/feature/features.go	55.26% <0.00%> (-3.08%)	⬇️

... and 1 file with indirect coverage changes

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[karthikmurali60]

@creydr I have made the necessary changes, can you please review this PR when you get a chance? Thanks !!

[creydr]

Thanks a lot for your contribution!
/lgtm
/approve

[knative-prow]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: creydr, karthikmurali60

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