Track Chatto 0.4.11

Regenerated proto bindings from upstream: no wire changes vs 0.4.10.
Bumped version 0.4.10 → 0.4.11 to keep chattolib aligned with the
Chatto server release per the version-tracks-Chatto policy.

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "chattolib"
-version = "0.4.10"
+version = "0.4.11"
 description = "Async Python client library for the Chatto webchat Connect API"
 requires-python = ">=3.11"
 license = "MPL-2.0 AND Apache-2.0"