feat: update plan upgrade CTA label

[jordanh]

Description

I was running through the app on an un-upgraded team and noticed the CTA to upgrade under TeamSettings was "Upgrade Team to Team" which read a bit oddly to me. It wasn't clear that "Team" was a plan you could buy. Without reading the description text near the CTA, I would have thought, "wait, isn't my team already a team?"

This trivial change changes the CTA to read "Upgrade to Team Plan"

Adding @nickoferrall to the PR review just in case there was some intention behind this CTA I missed

Final checklist

• I checked the code review guidelines
• I have added Metrics Representative as reviewer(s) if my PR invovles metrics/data/analytics related changes
• I have performed a self-review of my code, the same way I'd do it for any other team member
• I have tested all cases I listed in the testing scenarios and I haven't found any issues or regressions
• Whenever I took a non-obvious choice I added a comment explaining why I did it this way
• I added the label Skip Maintainer Review Indicating the PR only requires reviewer review and can be merged right after it's approved if the PR introduces only minor changes, does not contain any architectural changes or does not introduce any new patterns and I think one review is sufficient'
• PR title is human readable and could be used in changelog