remove matplotlib from dependencies

docs/source/conf.py

@@ -106,7 +106,6 @@ intersphinx_mapping = {
     "Python": ("https://docs.python.org/", None),
     "NumPy": ("http://docs.scipy.org/doc/numpy/", None),
     "SciPy": ("http://docs.scipy.org/doc/scipy/reference", None),
-    "matplotlib": ("http://matplotlib.org", None),
     "xarray": ("https://docs.xarray.dev/en/stable/", None),
     "pint": ("https://pint.readthedocs.io/en/stable/", None),
     "pytest": ("https://docs.pytest.org/en/7.1.x/", None),

pyproject.toml

@@ -34,7 +34,6 @@ classifiers = [
     "Topic :: Utilities",
 ]
 dependencies = [
-    "matplotlib>=3",
     "numpy>=1.14.5",
     "scipy>=1.9.0",
     "pyevtk>=1.1.1",