chore(deps): Hold back tree-sitter-language-pack 1.9.0

1.9.0 drops its explicit tree-sitter dependency and bundles a newer
core whose parse() rejects bytes, breaking the Dart and R parsers
(TypeError: 'bytes' object is not an instance of 'str'). Keep it at
>=1.5.0,<1.6.3 for now; the upgrade will be handled in a separate PR.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: GoodbyePlanet

pyproject.toml

@@ -31,7 +31,7 @@ dependencies = [
     "tree-sitter-bash>=0.25.0",
     "tree-sitter-sql>=0.3.0",
     "tree-sitter-lua>=0.5.0",
-    "tree-sitter-language-pack>=1.9.0,<1.9.1",
+    "tree-sitter-language-pack>=1.5.0,<1.6.3",
     "pydantic-settings>=2.14.1",
     "pyyaml>=6.0",
     "httpx>=0.28.0",