address review comments

.github/workflows/ci-wheels.yml

@@ -50,7 +50,7 @@ jobs:
     - name: "build ${{ matrix.os }} (${{ matrix.arch }}) wheels"
       uses: pypa/[email protected]
       env:
-        CIBW_SKIP: "cp313-* pp* *-musllinux*"
+        CIBW_SKIP: "cp39-* cp313-* pp* *-musllinux*"
         CIBW_ARCHS: ${{ matrix.arch }}
         CIBW_BUILD_FRONTEND: "build"
         CIBW_MANYLINUX_X86_64_IMAGE: "manylinux2014"

pyproject.toml

@@ -23,9 +23,9 @@ classifiers = [
     "Operating System :: Unix",
     "Programming Language :: Python",
     "Programming Language :: Python :: 3 :: Only",
-    "Programming Language :: Python :: 3.9",
     "Programming Language :: Python :: 3.10",
     "Programming Language :: Python :: 3.11",
+    "Programming Language :: Python :: 3.12",
     "Programming Language :: Python :: Implementation :: CPython",
     "Topic :: Scientific/Engineering",
     "Topic :: Scientific/Engineering :: Atmospheric Science",
@@ -46,7 +46,7 @@ keywords = [
 ]
 license = {text = "BSD-3-Clause"}
 name = "stratify"
-requires-python = ">=3.9"
+requires-python = ">=3.10"
 
 [project.urls]
 Code = "https://github.com/SciTools-incubator/python-stratify"
@@ -69,7 +69,7 @@ write_to = "src/stratify/_version.py"
 local_scheme = "dirty-tag"
 
 [tool.black]
-target-version = ["py39", "py310", "py311"]
+target-version = ["py310", "py311", "py312"]
 line-length = 88
 include = '\.pyi?$'