Bump version to 2.1.0

This is the last minor release before the next major release (3.0),
which will be fully Python native without bundled DLL/SO libraries.

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: gijzelaerr

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "python-snap7"
-version = "2.0.2"
+version = "2.1.0"
 description = "Python wrapper for the snap7 library"
 readme = "README.rst"
 authors = [