Remove svg checkmark from editor toolbar

[stefanprobst]

Summary

This PR removes the svg checkmark which is added to the editor toolbar successful status check, because it

• causes The browser Safari indicated that there is a missing image #5411 for safari users
• does not show for me in chrome or firefox
• is inconsistent because the "danger" state does not try to add an svg

Test plan

none (but snapshots have been updated)

Checklist

Please add a x inside each checkbox:

• I have read the contribution guidelines.
• Code is formatted via running yarn format.
• Tests are passing via running yarn test.
• The status checks are successful (continuous integration). Those can be seen below.

[erezrokah]

Thanks @stefanprobst, I was not able to see the checkmark as well in various browsers.