Add Toki Pona to list of languages

[tbodt]

https://iso639-3.sil.org/code/tok

[quiple]

It's a duplicate of #5998

[auroursa]

In the current code, a languages without have code2 will not be available as options for the post language (as I mentioned in #5998). Unfortunately, Toki Pona is not included in the ISO 639-1 list, so it does not have code2.

Some other popular languages also lack code2, and it seems we may need to make more changes, possibly involving server-side adjustments. But I’m not sure about Bluesky's future development direction, so it might be best for the developers to handle this.

[tbodt]

Understandable. 2-character codes are basically legacy, no more will be added. What's funny is I've never seen any other software that needs to distinguish between 2 and 3 char codes...they're just the language codes and some are longer.