Temporary fix for a starship bug not accepting negative return values

[eugenesvk]

I've been bugged a lot by weird starship error messages when I abort some commands, then finally found out that for some reason starthip can't accept negative values as return status numbers I've filed a bug upstream https://github.com/starship/starship/issues/4980, but in the meantime am using this commit to always return positive command return status values

[anki-code]

I commented the cause in upstream issue and made changes. Good catch thanks!