Add matplotlib and zstandard as core dependencies

Both are now required (not optional):
- matplotlib: needed for palette colormap (ListedColormap) and
  da.xrs.plot() with palette TIFFs
- zstandard: needed for ZSTD compression (tag 50000), increasingly
  common in modern COGs

This fixes the CI failures where these packages weren't installed.

Author: brendancol

setup.cfg

@@ -23,6 +23,8 @@ install_requires =
     scipy
     xarray
     numpy
+    matplotlib
+    zstandard
 packages = find:
 python_requires = >=3.12
 setup_requires = setuptools_scm

xrspatial/geotiff/tests/test_features.py

@@ -2140,7 +2140,7 @@ def test_palette_8bit_read(self, tmp_path):
         assert da.dtype == np.uint8
         np.testing.assert_array_equal(da.values, pixels)
 
-        # Should have a cmap in attrs
+        # Should have cmap and colormap_rgba in attrs
         assert 'cmap' in da.attrs
         assert 'colormap_rgba' in da.attrs