Bump version to 4.0.0a3

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: gmr

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "rejected"
-version = "4.0.0a2"
+version = "4.0.0a3"
 description = "Rejected is a Python RabbitMQ Consumer Framework and Controller Daemon"
 readme = "README.md"
 requires-python = ">=3.11"