Drop Python 3.9 support, update to Python 3.10-3.13

- Update pyproject.toml requires-python to >=3.10
- Remove Python 3.9 classifier, add Python 3.13 classifier
- Update GitHub Actions tests to use Python 3.10 and 3.13

Author: benjeffery

.github/workflows/tests.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        python: [3.9, 3.12]
+        python: ["3.10", 3.13]
         os: [macos-latest, ubuntu-24.04, windows-latest]
         sys: [mingw64, ucrt64]
         env: [x86_64, ucrt-x86_64]

CHANGELOG.rst

@@ -2,6 +2,8 @@
 UPCOMING - [1.1.1]
 ******************
 
+- Drop Python 3.9 support, require Python >= 3.10 (:pr:`397`, :user:`benjeffery`)
+
 
 ********************
 [1.1.0] - 2025-08-16

pyproject.toml

@@ -21,15 +21,15 @@ classifiers = [
     "Operating System :: Microsoft :: Windows",
     "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",
     "Topic :: Scientific/Engineering",
     "Topic :: Scientific/Engineering :: Bio-Informatics",
 ]
 keywords = ["tree sequences", "tskit"]
-requires-python = ">=3.9"
+requires-python = ">=3.10"
 dependencies = [
     "msprime>=1.0.1",
     "tskit",