fix: shorten cluster name to fit into 32 chars limit

[kravciak]

Description

k3d has limit of 32 characters for cluster name.
This variable is not used for debugging, we can switch to shorter / less readable name.

FATA[0000] Failed Cluster Configuration Validation:  provided cluster name 'kubewarden-kubewarden-controller-private' does not match requirements: Cluster name must be <= 32 characters, but has 40

[Copilot]

Pull request overview

Adjusts the k3d cluster name used by the E2E GitHub Actions workflow to avoid k3d’s 32-character cluster name limit, preventing cluster creation failures in CI.

Changes:

• Update K3D_CLUSTER_NAME to use ${{ github.run_id }} instead of the repository name component to shorten the generated cluster name.

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[viccuad]

Thanks!

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 80.40%. Comparing base (89d5460) to head (2905189).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1669      +/-   ##
==========================================
- Coverage   80.43%   80.40%   -0.03%     
==========================================
  Files         127      127              
  Lines       16411    16411              
==========================================
- Hits        13200    13196       -4     
- Misses       3211     3215       +4     

Flag	Coverage Δ
rust-tests	80.40% <ø> (-0.03%)	⬇️

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