Temporarily skip all _to_numpy tests on macOS

Author: seisman

pygmt/tests/test_clib_to_numpy.py

@@ -13,6 +13,12 @@
 from pygmt.clib.conversion import _to_numpy
 from pygmt.helpers.testing import skip_if_no
 
+# Skip all tests on macOS.
+pytestmark = pytest.mark.skipif(
+    sys.platform == "darwin",
+    reason="For unknown reasons, tests in the file cause unrelated failures on macOS.",
+)
+
 try:
     import pyarrow as pa