epic: Loadtest Follow Ups #228

Description

This epic is an umbrella collection of work items we have identified through our load testing.

Readme if you are working on items from this epic

You can easily setup your own full test environment with a sharded kcp and all loadtesting tools (prometheus, Grafana, pyroscope) on Gardener, which will help you a ton in reproducing these issues.

1. Simply follow this guide here to setup the Gardener cluster
   https://github.com/platform-mesh/loadtest-internals/tree/main

2. and afterwards you can use the regular loadtest setup script from kcp to install everything that is required
   For now it is on this branch, I will update this once it's merged to main
   https://github.com/SimonTheLeg/kcp/tree/level-1-loadtest/test/load/setup