keyword_language is unused, renderet to parser.c as aux_sym_*

[LeoniePhiline]

While preparing helix-editor/helix#7387 I noticed that a (keyword_language) query makes tree-sitter fail parsing with a NodeType error.

Upon investigation, I found that:

The symbol is defined in grammar.json.

But it is not defined in node-types.json.

In parser.c, it is defined as aux_sym_keyword_language_token1. 🤔 (see also the codegen)

(keyword_language) appears to be unused.

I think it can be removed - or shall it be used for function_language?

[DerekStride]

I changed function_language to reference the keyword the query should work as expected on the latest version of the parser.