Fix: propagate EventPolicy filter to underlying Channels EventPolicy

[creydr]

The filters of the parent policy of Channels/Parallels & Sequences are not propagated to the underlying channels EventPolicies.
This PR fixes it.

Found on adding e2e tests in #8162

[codecov]

Codecov Report

Attention: Patch coverage is 77.77778% with 2 lines in your changes missing coverage. Please review.

Project coverage is 67.52%. Comparing base (2b92299) to head (7cea68e).
Report is 1 commits behind head on main.

Files	Patch %	Lines
pkg/reconciler/parallel/resources/eventpolicy.go	0.00%	2 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #8163   +/-   ##
=======================================
  Coverage   67.51%   67.52%           
=======================================
  Files         371      371           
  Lines       17974    17980    +6     
=======================================
+ Hits        12136    12141    +5     
- Misses       5066     5067    +1     
  Partials      772      772           

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[Cali0707]

/lgtm

Thanks for catching & fixing this @creydr !!

[knative-prow]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: Cali0707, creydr

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[Cali0707]

/test unit-tests

looks like a flake..