chore: bump version to 4.3.0 for next development cycle

- Move from accidentally released 4.2.0 to intended 4.3.0
- Beta workflow will now create v4.3.0b1, v4.3.0b2, etc.
- Maintains clear version lineage for development

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: sidmohan0

datafog/__about__.py

@@ -1 +1 @@
-__version__ = "4.2.0b1"
+__version__ = "4.3.0"