Update link size in work items time tracking

What does this MR do and why?

Updates link size in time tracking to 12px to match surrounding text and the design.

References

Please include cross links to any resources that are relevant to this MR This will give reviewers and future readers helpful context to give an efficient review of the changes introduced.

• Use smaller font size for time tracking links i... (#502855 - closed)
• Original design

MR acceptance checklist

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Screenshots or screen recordings

Screenshots are required for UI changes, and strongly recommended for all other merge requests.

Before	After

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

1. Open a task
2. Add a time spent to see state with just spent
3. Add a time estimate to see state with both (state with just estimate is same as with both)

Related to #502855 (closed)