Remove created prefix if aborted with --platform

[Hind-M]

Fix #2736

[jonashaag]

Thanks, LGTM, although I wonder if we can't create the file only after successful creation?

Otherwise instead of prompting the user which might be confusing, can we detect if the env folder was created by Mamba and if yes delete it?

[Hind-M]

Thanks, LGTM, although I wonder if we can't create the file only after successful creation?

I suppose we theoretically can, but it would probably be more prone to future bugs? The prefix directory is created to update the given platform info in the .mambarc file which could be required somehow, somewhere...

Otherwise instead of prompting the user which might be confusing, can we detect if the env folder was created by Mamba and if yes delete it?

Yeah I changed it now to detect creation and avoid passing config too...

[jonashaag]

Thanks! I suggest renaming to remove_prefix_on_failure or something like that because we don't remove it in all cases