Drop wheel from build requirements; no longer needed as of setuptools 70.1

[kandersolar]

• [ ] Closes #xxxx
• I am familiar with the contributing guidelines
• [ ] Tests added
• [ ] Updates entries in docs/sphinx/source/reference for API changes.
• Adds description and name entries in the appropriate "what's new" file in docs/sphinx/source/whatsnew for all changes. Includes link to the GitHub Issue with :issue:`num` or this Pull Request with :pull:`num`. Includes contributor name and/or GitHub username (link with :ghuser:`user`).
• [ ] New code is fully documented. Includes numpydoc compliant docstrings, examples, and comments where necessary.
• Pull request is nearly complete and ready for detailed review.
• Maintainer: Appropriate GitHub Labels (including remote-data) and Milestone are assigned to the Pull Request and linked Issue.

The wheel readme says:

This project used to contain the implementation of the setuptools bdist_wheel command, but as of setuptools v70.1, it no longer needs wheel installed for that to work. Thus, you should install this only if you intend to use the wheel command line tool!

So if we upgrade our minimum setuptools to 70.1, we don't need to list wheel in pyproject.toml anymore.

[echedey-ls]

Straight forward LGTM. No other significant occurrences of wheel in the project and build process works flawlessly. Well done on reviewing the build process :)