Fix overlaps for Multi-channel Signed Distance Field (MSDF) font rendering

[jupiterbjy]

When MSDF rendering is used, overlap sections are creating 'holes' in fonts.

To quote from Godot document:

Fonts with self-intersecting outlines will not render correctly in MSDF mode. If you notice rendering issues on fonts downloaded from websites such as Google Fonts, try downloading the font from the font author's official website instead.

However, since this font is directly from jetbrains site I believe this intersections exists from source.

Despite this font isn't widely used as general-purpose font, would totally appreciate such fix because I want to use this font for everything - as much that I wish my tombstone carved in jetbrains mono.