chore: update allowed unresolved imports and modify prefix encoding

- Added "datrie.**" to the allowed unresolved imports in pyproject.toml.
- Changed the encoding method in LRUTrieCache from "latin-1" to "hex" for improved token representation.

Author: bradhilton

pyproject.toml

@@ -127,6 +127,7 @@ unused-ignore-comment = "ignore"
 allowed-unresolved-imports = [
     # tinker deps
     "tinker.**",
+    "datrie.**",
     # backend deps
     "accelerate.**",
     "awscli.**",

src/art/tinker/prefix_cache.py

@@ -7,8 +7,7 @@
 
 import datrie
 
-_TOKEN_BYTES = 4
-_TRIE_ALPHABET = "".join(chr(i) for i in range(256))
+_TRIE_ALPHABET = "0123456789abcdef"
 
 
 @dataclass(frozen=True)
@@ -32,7 +31,7 @@ def _encode_tokens(tokens: Sequence[int]) -> str:
         packed = bytearray()
         for token in tokens:
             packed.extend(struct.pack(">I", token))
-        return packed.decode("latin-1")
+        return packed.hex()
 
     def lookup(self, rendered_tokens: Sequence[int]) -> PrefixEntry | None:
         key = self._encode_tokens(rendered_tokens)