This version hash is used for the filename, and so browsers/CDNs cache based on it. Previously the version hash was based only on the list of requested icons. This can cause issues in a couple of situations, most commonly when developing themes with custom icons:
- A requested icon does not exist, and then later is added to the theme. The bundle output changes, but the hash did not
- The SVG content of an icon changes, but the name of the icon does not. The bundle output changes, but the hash did not