Use the build package to build sdist and wheel distributions

[seisman]

Description of proposed changes

Fixes#1797.

Reminders

• Run make format and make check to make sure the code follows the style guide.
• Add tests for new features or tests that would have caught the bug that you're fixing.
• Add new public functions/methods/classes to doc/api/index.rst.
• Write detailed docstrings for all functions/methods.
• If wrapping a new module, open a 'Wrap new GMT module' issue and submit reasonably-sized PRs.
• If adding new functionality, add an example to docstrings or tutorials.

Slash Commands

You can write slash commands (/command) in the first line of a comment to perform
specific operations. Supported slash commands are:

• /format: automatically format and lint the code
• /test-gmt-dev: run full tests on the latest GMT development version

[weiji14]

A bit unrelated, but why is matplotlib needed in the cache_data workflow? Isn't this GitHub Actions workflow just used to download files?

I see that the matplotlib dependency was added at 270e3ea in #1310, but can't see exactly why this is needed.

[seisman]

pygmt/pygmt/helpers/testing.py

Line 8 in 8fe2d33

frommatplotlib.testing.compareimportcompare_images

matplotlib is imported in testing.py so when we run the download_test_data function, matplotlib must be imported.

[weiji14]

Ah ok. Seems like that import line could just be put inside the check_figures_equal function, but let's just keep things the way it is right now.

[weiji14]

Oh, and just noting that we should double check that the wheel and source files on TestPyPI look ok once this PR is merged.

[weiji14]

Ok for me on Linux. Might pay to know if this works locally on macOS and Windows as well, but the CI does look ok.