feat: support ClusterTrustBundle in CACertificateRefs

[zirain]

xref: https://github.com/envoyproxy/gateway/issues/6351

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 53.99240% with 121 lines in your changes missing coverage. Please review.

Project coverage is 71.06%. Comparing base (c368610) to head (7584d67). Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
internal/provider/kubernetes/controller.go	29.52%	71 Missing and 3 partials :warning:
internal/provider/kubernetes/controller_watch.go	30.00%	13 Missing and 1 partial :warning:
internal/provider/kubernetes/predicates.go	72.72%	9 Missing and 3 partials :warning:
internal/provider/kubernetes/indexers.go	74.28%	7 Missing and 2 partials :warning:
internal/gatewayapi/backendtlspolicy.go	40.00%	5 Missing and 1 partial :warning:
internal/gatewayapi/clienttrafficpolicy.go	73.91%	4 Missing and 2 partials :warning:

:x: Your patch check has failed because the patch coverage (53.99%) is below the target coverage (60.00%). You can increase the patch coverage or adjust the target coverage.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #6353      +/-   ##
==========================================
+ Coverage   70.78%   71.06%   +0.28%     
==========================================
  Files         224      225       +1     
  Lines       38648    38883     +235     
==========================================
+ Hits        27357    27634     +277     
+ Misses       9701     9653      -48     
- Partials     1590     1596       +6     

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.

:rocket: New features to boost your workflow:

• :snowflake: Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• :package: JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[zirain]

wait https://github.com/envoyproxy/gateway/pull/6352

[arkodg]

thanks @zirain, one minor comment, else LGTM