That is not a Graphviz version. Graphviz versions run from (approximately) 2.43 to (approximately) 3.0. I believe you are seeing the version number of the Python-to-Graphviz interface.
Read this graphviz · PyPI and note the text that says:
To render the generated DOT source code, you also need to install Graphviz (download page, archived versions, installation procedure for Windows).
I wish they would rename their interface and/or improve their documentation.