Fix contributors graph width

What does this MR do?

This MR is an attempt to fix the Contributors Graph width to show all commits that are in the graph. Currently, the graph is rendered wider than its surrounding div, which makes latest commits invisible to the user.

Are there points in the code the reviewer needs to double check?

Please test the project contributors page in a running instance of GitLab. I was unable to build and run GitLab on my machine as I am using Windows 7, so this change is done in a best-effort manner. 🤞

Finally, I was able to run it on Ubuntu using GitLab Development Kit. See the screenshots below.

Why was this MR needed?

This MR attemts to fix #22647 (closed) which constantly annoyed me and probably many others.

Screenshots (if relevant)

Before (large screen):

After (large screen):

Before (small screen):

After (small screen):

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• API support added
• Tests added for this feature/bug
• Review
  • Has been reviewed by UX
  • Has been reviewed by Frontend
  • Has been reviewed by Backend
  • Has been reviewed by Database
• Conform by the merge request performance guides
• Conform by the style guides
• Squashed related commits together
• Internationalization required/considered
• End-to-end tests pass (package-and-qa manual pipeline job)

What are the relevant issue numbers?

#22647 (closed)