[CI] whitelist dl.k8s.io in GHA

[AshleyDumaine]

What this PR does / why we need it: Needed for #892 since some of the workflows use pull_request_target which checks main's workflow files 🙃

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #

Special notes for your reviewer:

TODOs:

• squashed commits
• includes documentation
• adds unit tests
• adds or updates e2e tests

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 65.96%. Comparing base (5bbc997) to head (4fa8df7).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #893   +/-   ##
=======================================
  Coverage   65.96%   65.96%           
=======================================
  Files          71       71           
  Lines        7956     7956           
=======================================
  Hits         5248     5248           
  Misses       2406     2406           
  Partials      302      302           

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