Remerge ipynbdiff as vendor

What does this MR do and why?

Merging !90696 (merged) caused issues with deploying review apps. !91397 (merged) reverted that commit, and this MR is intended to fix the error and reintroduce ipynbdiff into the as a vendored gem.

Issue on errors due to !90696 (merged): #366536 (closed)

How to set up and validate locally

This is fixed if the review stage of the pipeline passes

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.