ci(load-tests): add GitHub Actions workflow for load testing on k8s

[Elvis339]

Why this should be merged

Enables CI execution on platform-chaos-k8s addressing three critical EVM performance testing requirements:

1. Access to larger nodes than GitHub provides
2. Controlled latency simulation between nodes using chaos mesh for geographic distribution testing
3. Secure cluster access without exposing credentials to GitHub Actions.

This foundation supports the EVM performance testing initiative and future regression analysis capabilities.

How this works

GitHub workflows can now leverage platform-chaos-k8s infrastructure for EVM load testing. Workflows automatically provision test environments. This provides a self-service testing environment without requiring direct cluster access or manual infrastructure setup.

How this was tested

• https://github.com/ava-labs/avalanchego/actions/runs/15978698247/job/45067717343

Need to be documented in RELEASES.md?

No

[Copilot]

Pull Request Overview

Adds a new GitHub Actions workflow to run EVM load tests against a Kubernetes cluster using a custom self-hosted runner and Nix for environment management.

• Introduces .github/workflows/load-tests.yaml for on-demand load testing via workflow_dispatch
• Configures dependencies (apt, Go, Nix) inside a container and checks out full repository history
• Executes Go-based load tests with a Nix-powered shell

Comments suppressed due to low confidence (1)

.github/workflows/load-tests.yaml:32

• Enhance robustness by prepending the script with set -euo pipefail so the job fails fast on any command error or undefined variable within the shell step.

        shell: nix develop --command bash -x {0}