Set dependency to Python >= 3.10

Numpy 2 needs this, and we depend on that. So, it's a good idea to
explicitly not support older versions instead of claiming something wrong.

.github/workflows/lint.yml

@@ -20,7 +20,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v5
         with:
-          python-version: 3.9
+          python-version: "3.10"
 
       - name: Install Python dependencies
         run: pip install black flake8

.github/workflows/packaging.yml

@@ -19,7 +19,7 @@ jobs:
     strategy:
       max-parallel: 4
       matrix:
-        python-version: [3.9]
+        python-version: ["3.10"]
 
     steps:
     - uses: actions/checkout@v1

.github/workflows/tox_checks.yml

@@ -33,10 +33,10 @@ jobs:
       - name: Git clone
         uses: actions/checkout@v2
 
-      - name: Set up Python ${{ env.default_python || '3.9' }}
+      - name: Set up Python ${{ env.default_python || '3.10' }}
         uses: actions/setup-python@v5
         with:
-          python-version: "${{ env.default_python || '3.9' }}"
+          python-version: "${{ env.default_python || '3.10' }}"
 
       - name: Pip cache
         uses: actions/cache@v2

.github/workflows/tox_pytests.yml

@@ -17,7 +17,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [3.9, "3.10", "3.11"]
+        python-version: ["3.10", "3.11", "3.12", "3.13"]
 
     steps:
     - uses: actions/checkout@v1

pyproject.toml

@@ -47,13 +47,14 @@ classifiers = [
     "Operating System :: OS Independent",
     "Programming Language :: Python",
     "Programming Language :: Python :: 3",
-    "Programming Language :: Python :: 3.9",
     "Programming Language :: Python :: 3.10",
     "Programming Language :: Python :: 3.11",
+    "Programming Language :: Python :: 3.12",
+    "Programming Language :: Python :: 3.13",
     "Programming Language :: Python :: Implementation :: CPython",
     "Topic :: Utilities",
 ]
-requires-python = ">=3.8"
+requires-python = ">=3.10"
 dependencies = [
     "blinker",
     "dill",

tox.ini

@@ -11,9 +11,10 @@ envlist =
 
 [gh-actions]
 python =
-    3.9: py39
     3.10: py310
     3.11: py311
+    3.12: py312
+    3.13: py313
 
 [testenv]
 basepython =
@@ -114,8 +115,8 @@ deps =
     pytest-cov
 
 
-[testenv:py39]
-basepython = {env:TOXPYTHON:python3.9}
+[testenv:py312]
+basepython = {env:TOXPYTHON:python3.12}
 setenv =
     {[testenv]setenv}
 usedevelop = true
@@ -125,8 +126,8 @@ deps =
     {[testenv]deps}
     pytest-cov
 
-[testenv:py38]
-basepython = {env:TOXPYTHON:python3.8}
+[testenv:py313]
+basepython = {env:TOXPYTHON:python3.13}
 setenv =
     {[testenv]setenv}
 usedevelop = true