devel/interactive_rebase_tool: Update to 2.2.1

ChangeLog:
https://github.com/MitMaro/git-interactive-rebase-tool/releases/tag/2.2.1

Crash on multibyte strings in commit diff view

PR: 267660
Reported by: petteri.valkonen@iki.fi (maintainer)
MFH: 2022Q4 (bugfix)