Circles in "think" bubble's tail aren't closed in Firefox

[adroitwhiz]

Expected Behavior

The two circles in a "think" bubble's tail should appear as completely closed circles.

Actual Behavior

In Firefox, there's a small gap in the stroke around the circles, likely due to floating-point error making ctx.arc not complete a full circle:

Steps to Reproduce

1. Open Scratch in Firefox
2. Click the "think (Hmm...)" block
3. Enter full-screen mode and look at the bubble

System Details

Firefox 122 on Fedora

Screenshots
See above