Many remote files are cached as GitHub Actions assets to be reused in CI workflows. These files are listed in the pygmt/helpers/caching.py file. See below:

Currently, the list is a little messy. Some potential improvements:

1. Put some comments (e.g., "Names like @N35E135.earth_relief_03s_g.nc are for internal use only.") at the start of the list.
2. Remove some comments like "# Specific grid for 15s test"
3. Update the order of some entries. First categorize files into groups and sort alphabetically in each group.

Helps are welcome.