Fix incorrect description of surface_azimuth parameter in get_pvgis_hourly

[tongpu]

• Closes pvlib.iotools.get_pvgis_hourly's surface_azimuth parameter doesn't use pvlib's azimuth convention #1724
• 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.

Fixes a documentation issue introduced with the change to align surface_azimuth in pvgis_get_hourly, where the implementation is clockwise from north, but the documentation strings mention counter-clockwise from north.

[kandersolar]

Thanks for catching and fixing this error @tongpu! Can you list yourself as a contributor and make a note about this doc correction in the 0.10.2 whatsnew file? https://github.com/pvlib/pvlib-python/blob/main/docs/sphinx/source/whatsnew/v0.10.2.rst

[tongpu]

I've added an update to the docs section.

[cwhanse]

Thanks @tongpu

[kandersolar]

LGTM, thanks @tongpu