add Grand Canyon University to brands/amenity/university

[Shubham0523]

This PR adds Grand Canyon University to the brands/amenity/university category in the NSI.

• Wikidata ID: Q1378857
• Reason for inclusion: Grand Canyon University is a for-profit institution that operates like a branded business, with a strong online presence and physical campuses across the U.S. Its model is aligned with other universities already included in the index, such as the University of Phoenix.
• Meets NSI requirements: Grand Canyon University has multiple locations and meets the threshold for inclusion due to its presence as a for-profit educational entity with a valid Wikidata tag.

Additional Notes

Grand Canyon University will improve the accuracy of university tagging for similar institutions in OpenStreetMap and help with mapping for-profit educational institutions in regions where they operate.

[bhousel]

Wikipedia says there is only 1 main campus and 8 off campus nursing schools.
https://en.wikipedia.org/wiki/Grand_Canyon_University

It would be less work for someone to just open OSM and add these things, than for it to be a preset in NSI.

[Shubham0523]

Thanks for the clarification. Based on this feedback, I'll close the PR and look into other potential contributions.