Adding RateLimiter to LLM unit tests, plus improving system-chat prompt to work…

Adding RateLimiter to LLM unit tests, plus improving system-chat prompt to work better for both llama 70b, gpt-3.5-turbo, and gpt-4o-mini.
4 jobs from emoji-behaviors in 2 minutes 10 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Build
passed #41010
minecraft
build_mod

02:10

 
  Test
manual #41011
minecraft allowed to fail manual
gpt-3.5-turbo
manual #41012
minecraft allowed to fail manual
gpt-4o
manual #41013
minecraft allowed to fail manual
llama3-8b