Locally? Our devs can do whatever they want. For anything I'm working on, for local deployments and testing, I generally build it out so it's set in Makefile/Taskfile. If you're running your determinstic tests locally it should really just be a single command that bootstraps everything and runs the tests, or updates a certain part of your app and runs the tests. The LLM shouldn't need credentials in that instance.
Regardless I'm deploying a local stack of some sort all the credentials and everything are probably stored locally or in an env var where the llm will have access. So if I was having the LLM drive a browser during active development, it can look at the files.
Sure, I guess we could put in the top level markdown more details about this... but why? It takes little time or context for it to figure it out. We have shit change so frequently that it's just something else we have to maintain.