This removes the minimum thickness clamping in the shader.
The reason why this was clamped in the first place was to reduce
aliasing artifacts. With the new super sampling method for
rendering, this should no longer be an issue.
Note: This can break visual compatibility, but the previous radii
were arguably "wrong". This essentially fixes this and renders
the strokes with the actual radii from the attribute.
Previous files that might have relied on the clamping will have
to be updated.
Pull Request: https://projects.blender.org/blender/blender/pulls/138119
1d6f313995