v1.31.2

### Fixes

- Update single-file-core to 1.6.32:
  - "Remove unused fonts" no longer drops the `unicode-range` subsets holding the icon glyphs of fonts that set them through a custom property, such as Font Awesome 7 (`.fa-x-twitter { --fa: "\e61b" }` behind `::before { content: var(--fa) }`). The characters the browser reports having drawn with each family now count in the `unicode-range` tests, so the icons are no longer rendered with the fallback font.
  - The displayed `srcset` candidate keeps its descriptor when the alternative images are removed. A `240w` candidate under `sizes="200px"` or a `2x` candidate was written as a bare `src`, so a layout reading the intrinsic width of the image drew it larger than on the original page.
  - JPEG XL images are named `.jxl` in self-extracting ZIP archives even when their URL carries no extension, and are extracted as `image/jxl` instead of `application/octet-stream`.