attempt to index a userdata value on subsequent calls to require

[TorchedSammy]

i noticed while trying to add treesitter support to lite xl, any calls after the 1st to ltreesitter.require causes an attempt to index a userdata value error. it seems that on the call after 1st it returns a plain userdata value (somehow) instead of an ltreesitter parser as testing in lua repl shows:

[euclidianAce]

I've fixed this on my end with the above commit. Thanks for reporting and let me know if the issue persists!

[takase1121]

According to @TorchedSammy it still happens.

[TorchedSammy]

(in lite-xl; seems to be fixed with the same testing in lua repl)