Can't process commas inside --var parameters

[miromasat]

It so seems that gh models has an issue working with commas (and possibly other special) when passing these as --var parameters.

example of successful call:
gh models run --file travel.prompt.yml --var city="paris and milan"

example of failed call:
gh models run --file travel.prompt.yml --var city="paris, milan"

Also attached as screenshot below.

[cschleiden]

Try:

gh models run --var \"city=paris,milan\"

[sgoedecke]

Done in PR #85