Truncate long tags in runners table

What does this MR do?

Truncates long tags in the runners table.

What are the relevant issue numbers?

gitlab-ee#9420

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary — N/A
• Documentation created/updated via this MR — N/A
• Documentation reviewed by technical writer or follow-up review issue created — N/A
• Tests added for this feature/bug
• Tested in all supported browsers
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the database guides — N/A
• Link to e2e tests MR added if this MR has Requires e2e tests label. See the Test Planning Process. — N/A
• Security reports checked/validated by reviewer