Add Conformance Tests for virtual mode

[enrichman]

Fix #399

This PR adds the Conformance Tests CI for the virtual mode.

See https://github.com/cncf/k8s-conformance

A test result can be seen here: https://github.com/enrichman/k3k/actions/runs/18871535458

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 59.48%. Comparing base (bf70e0d) to head (bf820f9).

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #534   +/-   ##
=======================================
  Coverage   59.48%   59.48%           
=======================================
  Files          56       56           
  Lines        5132     5132           
=======================================
  Hits         3053     3053           
  Misses       1804     1804           
  Partials      275      275           

Flag	Coverage Δ
cli	53.17% <ø> (+0.10%)	⬆️
controller	58.23% <ø> (ø)
e2e	58.23% <ø> (ø)
unit	41.70% <ø> (ø)

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[raulcabello]

LGTM