update release version to 4.0.0

Author: arun3688

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "OMPython"
-version = "3.6.0"
+version = "4.0.0"
 description = "OpenModelica-Python API Interface"
 readme = "README.md"
 authors = [