feat: use py limited ABI

.github/workflows/build.yaml

@@ -15,7 +15,7 @@ jobs:
       matrix:
         os: [ubuntu-latest, windows-latest, macos-latest]
     env:
-      CIBW_SKIP: 'cp27-* cp35-* pp*'
+      CIBW_BUILD: 'cp36-*'
       CIBW_ARCHS_LINUX: auto aarch64
     steps:
       - name: Set up QEMU
@@ -24,11 +24,11 @@ jobs:
         with:
           platforms: arm64
       - uses: actions/checkout@v2
+      - uses: joerick/cibuildwheel@v1.9.0
       - uses: actions/setup-python@v2
         with:
           python-version: '3.9'
-      - run: pip install cibuildwheel
-      - run: cibuildwheel
+      # Install and test on 3.9 here!
       - uses: actions/upload-artifact@v2
         with:
           path: ./wheelhouse

setup.cfg

@@ -84,3 +84,6 @@ warn_unused_configs = true
 warn_unused_ignores = true
 warn_return_any = true
 warn_unreachable = true
+
+[bdist_wheel]
+py-limited-api = cp36

setup.py

@@ -9,7 +9,13 @@
 from setuptools import setup
 from setuptools.command.build_ext import build_ext
 
-ext_modules = [Extension("markupsafe._speedups", ["src/markupsafe/_speedups.c"])]
+ext_modules = [
+    Extension(
+        "markupsafe._speedups",
+        ["src/markupsafe/_speedups.c"],
+        py_limited_api=True,
+    )
+]
 
 
 class BuildFailed(Exception):