v1.1514.0

Copy KaTeX fonts as binary rather than text files

Set the `encoding` option to `false` [1] when copying KaTeX fonts so they are
treated as binary rather than text. This fixes an issue where the fonts were
corrupted in the process.

[1] https://gulpjs.com/docs/en/api/src/#options

Fixes https://github.com/hypothesis/client/issues/6526