Minor tree-sitter cleanups

Minor tree-sitter cleanups

* lisp/treesit.el (treesit-fontify-with-override): Fix docstring
grammar.  Remove redundant precondition (bug#64052).
* src/treesit.c (Ftreesit_parser_set_included_ranges): Fix typo in
commentary.
(treesit_predicate_equal, treesit_predicate_match)
(treesit_predicate_pred): Avoid fixnum roundtrip by using
list_length in place of Flength.  Make error messages more accurate.
(treesit_eval_predicates): Quote predicate names in error message.