Update python/runfiles/runfiles.py

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

Author: jklukas

python/runfiles/runfiles.py

@@ -36,8 +36,8 @@ class _RepositoryMapping(collections.abc.Mapping[Tuple[str, str], str]):
     Handles both exact mappings and prefix-based mappings introduced by the 
     --incompatible_compact_repo_mapping_manifest flag.
     
-    Implements the Mapping protocol for exact lookups, while providing a separate
-    lookup() method for prefix-aware resolution.
+    Implements the Mapping protocol, providing a unified lookup for both exact
+    and prefix-based mappings.
     """
 
     def __init__(