FR: Avoid ABI 15 language libraries in Emacs 30.1

[thromer]

Emacs 30.1 only supports ABI 13 and 14, but multiple language libraries are now at ABI 15 at head, resulting in Warning (treesit): The installed language grammar for X cannot be located or has problems (version-mismatch): 15.

So far I've been gradually updating treesit-language-source-alist, e.g.

(setq treesit-language-source-alist
      '((bash . ("https://github.com/tree-sitter/tree-sitter-bash" "v0.23.3" nil nil nil))
        (go . ("https://github.com/tree-sitter/tree-sitter-go" "v0.23.4" nil nil nil))
        (gomod . ("https://github.com/camdencheek/tree-sitter-go-mod" "v1.0.2" nil nil nil))
        (python . ("https://github.com/tree-sitter/tree-sitter-python" "v0.23.6" nil nil nil))))

But it would be nice if we could crowdsource determining the appropriate tags for each language library.

The first approach that occurs to me is adding a new abi14_revision key to the recipe function, encouraging the community to contribute values to that field in treesit-auto.el, and using that revision if (treesit-library-abi-version) returns 14.

Happy to help if that sounds like a good idea. I'm not attached to this specific approach.