Fix commit markdown parsing with word boundaries

What does this MR do and why?

Fix commit markdown parsing with word boundaries

• Previously we would match the cceededc in something like succeededc.
• #450246 (closed)

Changelog: fixed

MR acceptance checklist

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Screenshots or screen recordings

Before	After

How to set up and validate locally

1. Clone this project to local GDK
2. View project home and notice whether or not succeededc has a commit link in the commit box, file tree, and markdown content.
3. Markdown rendering is cached so you might need to invalidate markdown cache or you can try just adding a new commit to README.md that adds an empty line.

Related to #450246 (closed)

Thanks

Thanks so much to @alejandro && @sgarg_gitlab!