Add opt-in test group environment isolation#23

ChrisRackauckas-Claude wants to merge 4 commits into

SciML:mainSciML/SciMLTesting.jl:mainfrom

ChrisRackauckas-Claude:agent/isolate-test-group-environmentsChrisRackauckas-Claude/SciMLTesting.jl:agent/isolate-test-group-environmentsCopy head branch name to clipboard