Include load tests in CI pipeline after staging deployment

[wojciechos]

Add load tests in our CI pipeline for the pre-release phase on staging. These tests should ensure a success rate of at least 99.9% for all requests.

Acceptance Criteria

• Integrate load testing into the CI pipeline - all RPC methods.
• Tests should run automatically after each staging deployment.
• The success threshold should be set at 99.9% for request completions.