Bump GMT version from 6.2.0rc1 to 6.2.0rc2 in CI

[weiji14]

Description of proposed changes

Second release candidate of Generic Mapping Tools v6.2.0 at https://github.com/GenericMappingTools/gmt/releases/tag/6.2.0rc2.

Note: This PR also temporarily stops geopandas from being installed in the main test suite, see #1290 (comment) for the rationale.

Related to #1289, Supersedes #1218

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 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]

The Python 3.9 / NumPy 1.20 build can't get past the install step (see https://github.com/GenericMappingTools/pygmt/pull/1290/checks?check_run_id=2661062442#step:5:1). I think this is due to a package conflict with gmt and geopandas. Specifically, the gmt=6.2.0rc2 conda package is linked to GDAL 3.3, but geopandas requires fiona which only has packages up to GDAL 3.2. We'll need to wait for conda-forge/fiona-feedstock#179 before proceeding.

[seisman]

Perhaps we can temporarily remove "geopands" so we can proceed?

[weiji14]

Perhaps we can temporarily remove "geopands" so we can proceed?

Not a big fan of this idea, but yeah we might have to. What I might do is to remove geopandas from ci_tests.yaml, but install it in ci_tests_dev.yaml (while pinning to GDAL 3.2) so that we have some tests using geopandas at least (for coverage).

[seisman]

Looks good if all tests pass.

[weiji14]

Looks good if all tests pass.

Well, the tests won't all pass because we need to update 24 of them 🤣 But I'm assuming we'll update those in separate PRs later 😇