dpctl should not vendor versioneer, but use one from PyPI or conda-forge

[oleksandr-pavlyk]

dpctl uses versioneer.py to produce _version.py included in the installed package.

dpctl need not vendor the versioneer.py in its repo. It can get it either from PyPI, or from conda-forge.

Unfortunately, versioneer is not available on pkgs/main.

[oleksandr-pavlyk]

The versioneer's use instruction states:

1. Install versioneer from pip
2. Configure setup.cfg
3. Run versioneer install which copies some files in the project's layout to be vendored.

In view of this, closing this ticket.