julia

583981fb - Set temporary env whenever Julia is started with `--project=@temp` (#51149)

Set temporary env whenever Julia is started with `--project=@temp` (#51149) This makes it convenient to start and run Julia in a temporary environment. This brings `Pkg.activate(; temp=true)` functionality to cmdline. - Update relevant docs. - Add tests for `--project=@temp` and `JULIA_PROJECT="@temp"`.