fix typescript 5.5 compatibility

[Amixx]

This is a fix for an error after upgrading to typescript 5.5:

../node_modules/tom-select/src/vanilla.ts:100:51 - error TS1536: Octal escape sequences and backreferences are not allowed in a character class. If this was intended as an escape sequence, use the syntax '\x20' instead.

100    _classes = _classes.trim().split(/[\11\12\14\15\40]/);

I have tested the solution in one of my projects and it resolves the typescript error.

[fuzzzerd]

Also running into this error upgrading from Typescript 5.4 to 5.5. Would be great to see this merged and a new release created.

[Amixx]

@fuzzzerd it seems like this project has been abandoned unfortunately (I have tried to contact the maintainers). You can use my fork instead.