Remove all code references to Py2neo

[yunchae-kim]

As of PR-#92, the Py2neo package has been removed from the project's dependencies. To ensure the project's codebase is up to date, it's necessary to remove all references to the Py2neo package from the code.

This includes any imports, function calls, or code sections that use Py2neo-specific functionality. Review the entire codebase and make the necessary changes to eliminate any dependencies on Py2neo.