Remove dependency on unmaintained `json` crate

[scouten-adobe]

In #317, we added an indirect dependency on json crate which has been unmaintained for more than three years.

I've filed an issue at https://github.com/vstroebel/jfifdump/issues/4 asking the maintainer of jfifdump crate to consider alternatives.

Tracking issue to ensure we don't keep this dependency in the long term.

[scouten-adobe]

@adobe export issue to Jira project CAI

[github-jira-sync-bot]

:white_check_mark: Jira issue https://jira.corp.adobe.com/browse/CAI-4818 is successfully created for this GitHub issue.