Provide volume with OIDC token in SinkBinding

[creydr]

Fixes #7323

Proposed Changes

• 🎁 Provide OIDC token in SinkBinding as mountpoint under /oidc/token

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

How to verify change

• Install a broker: kn broker create my-broker --class MTChannelBasedBroker
• Install a container source (will add a sinkbinding under the hood and makes it easy to verify the binding through its deployment): kn source container create my-container-source --image gcr.io/knative-nightly/knative.dev/eventing/cmd/heartbeats:latest --env POD_NAME=pod-name --env POD_NAMESPACE=default --sink broker:my-broker
• Verify the container source deplyment has the volume with the token: kubectl get deploy my-container-source-deployment -o yaml
• Additionally you can check if the mounted secret contains a JWT: kubectl get secret oidc-token-my-container-source-sinkbinding -ojsonpath='{.data.token}' | base64 -d

Release Note

Provide OIDC token in SinkBinding under /oidc/token path.

[codecov]

Codecov Report

Attention: 17 lines in your changes are missing coverage. Please review.

Comparison is base (9431ce9) 76.76% compared to head (1a9cc48) 76.79%.
Report is 15 commits behind head on main.

Files	Patch %	Lines
pkg/auth/utils.go	53.84%	4 Missing and 2 partials ⚠️
pkg/auth/token_provider.go	0.00%	5 Missing ⚠️
pkg/apis/sources/v1/sinkbinding_lifecycle.go	93.54%	4 Missing ⚠️
cmd/webhook/main.go	0.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #7444      +/-   ##
==========================================
+ Coverage   76.76%   76.79%   +0.02%     
==========================================
  Files         253      253              
  Lines       13916    14098     +182     
==========================================
+ Hits        10683    10826     +143     
- Misses       2700     2732      +32     
- Partials      533      540       +7     

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[creydr]

/retest

[creydr]

@pierDipi could you recheck?

[pierDipi]

This is potentially longer than the max characters count, can we just use the SB name?

[creydr]

👍 updated to use kmeta.ChildName()

[pierDipi]

/lgtm
/approve

[knative-prow]

[APPROVALNOTIFIER] This PR is APPROVED

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

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[creydr]

/retest