Update the baseline image for pygmt/test/test_plot.py:test_plot_matrix

[seisman]

Description of proposed changes

See #1539 for the bug report and #1539 for the upstream fix.

Changes in this PR:

• Changing incols="0,1,2+s0.005" to incols="0,1,2+s0.5" so that circils are large enough to be visible
• Update the baseline image with the GMT master branch
• Mark the test as xfail for GMT <= 6.2.0

Fixes #1539.

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

[github-actions]

Summary of changed images

This is an auto-generated report of images that have changed on the DVC remote

Status	Path
modified	pygmt/tests/baseline/test_plot_matrix.png

Image diff(s)

Added images

Modified images

Path	Old	New
test_plot_matrix.png

Report last updated at commit f7d16e4