Drop unnecessary dependency on mock (#643)

Co-authored-by: David Stansby <[email protected]>
Co-authored-by: jakirkham <[email protected]>

Author: 3 people

pyproject.toml

@@ -50,7 +50,6 @@ docs = [
     "sphinx-issues",
     "pydata-sphinx-theme",
     "numpydoc",
-    "mock",
 ]
 test = [
     "coverage",