fix: skip reconciles on endpoint slices when endpoint routing not in use

[dboslee]

What this PR does / why we need it:

As the title states this PR skips unnecessary reconciles on endpoint slice events when endpoint routing is not used by the given gateway.

Which issue(s) this PR fixes: This addresses the issue here however I wouldn't necessary close it with this fix as there are likely additional issues that could be addressed to improve the overall robustness of the controller.

https://github.com/envoyproxy/gateway/issues/5344

Release Notes: No

[codecov[bot]]

Codecov Report

:x: Patch coverage is 61.90476% with 40 lines in your changes missing coverage. Please review. :white_check_mark: Project coverage is 71.09%. Comparing base (a4aa88d) to head (2a6b71f). :warning: Report is 218 commits behind head on main.

Files with missing lines	Patch %	Lines
internal/provider/kubernetes/predicates.go	61.90%	30 Missing and 10 partials :warning:

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5345      +/-   ##
==========================================
- Coverage   71.12%   71.09%   -0.03%     
==========================================
  Files         228      228              
  Lines       40690    40807     +117     
==========================================
+ Hits        28942    29013      +71     
- Misses      10055    10091      +36     
- Partials     1693     1703      +10     

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[arkodg]

we we also save on memory by not inserting the endpointslice into watchable by skipping it here https://github.com/envoyproxy/gateway/blob/d3f95cc50af9e975c34df9639f67ac23862731f2/internal/provider/kubernetes/controller.go#L398

[github-actions[bot]]

This pull request has been automatically marked as stale because it has not had activity in the last 30 days. Please feel free to give a status update now, ping for review, when it's ready. Thank you for your contributions!

[github-actions[bot]]

This pull request has been automatically marked as stale because it has not had activity in the last 30 days. Please feel free to give a status update now, ping for review, when it's ready. Thank you for your contributions!

[jukie]

Hey @dboslee could you fix the merge conflicts and add more test coverage?

[github-actions[bot]]

This pull request has been automatically marked as stale because it has not had activity in the last 30 days. Please feel free to give a status update now, ping for review, when it's ready. Thank you for your contributions!