Trim redundant parameter prose from decode_text docstring

The signature already conveys what max_size and label do; keep only the
non-obvious caveats about the errors handler and embedded-NUL truncation.

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

Author: antoineleclair

src/dqlitewire/types.py

@@ -254,7 +254,6 @@ def decode_text(
 ) -> tuple[str, int]:
     """Decode NUL-terminated UTF-8 text; return (text, bytes_consumed).
 
-    ``max_size`` caps decoded length; ``label`` names the field in errors.
     ``errors="replace"``/``"surrogateescape"`` yield codepoints the log
     sanitiser misses and that break encode_text round-trip. Embedded NULs in
     server data read back truncated at the first NUL (no length prefix).