DEP: drop support for CPython 3.9

Author: neutrinoceros

.github/workflows/release.yml

@@ -14,7 +14,7 @@ jobs:
       - name: "Set up Python"
         uses: "actions/setup-python@v4"
         with:
-          python-version: "3.9"
+          python-version: "3.10"
 
       - name: "Install build tool"
         run: "pip install --user build"

.github/workflows/test.yml

@@ -16,7 +16,6 @@ jobs:
           - "3.12"
           - "3.11"
           - "3.10"
-          - "3.9"
         pyqt-dependency:
           - "PyQt"
           - "PySide"

README.rst

@@ -14,7 +14,7 @@ Contact:
   Nathaniel J. Smith <njs@pobox.com> and Stéfan van der Walt <stefanv@berkeley.edu>
 
 Dependencies:
-  * Python 3.9+
+  * Python 3.10+
   * `colorspacious <https://pypi.python.org/pypi/colorspacious>`_ 1.1+
   * Matplotlib 3.5+
   * NumPy 1.22+

pyproject.toml

@@ -15,7 +15,7 @@ classifiers = [
   "Programming Language :: Python :: 3",
 ]
 
-requires-python = ">=3.9"
+requires-python = ">=3.10"
 dependencies = [
   "numpy >=1.22",
   "matplotlib >=3.5",
@@ -51,7 +51,7 @@ package-data = {viscm = ["examples/*"]}
 
 
 [tool.mypy]
-python_version = "3.9"
+python_version = "3.10"
 
 # These libraries don't have type stubs. Mypy will see them as `Any` and not
 # throw an [import] error.