ci: use legacy license definition to allow building on py3.9

.gitignore

@@ -8,6 +8,7 @@ doc/_build/
 gh-pages/
 build/
 dist/
+wheelhouse/
 .vscode/
 /__pycache__/
 *.egg-info/

pyproject.toml

@@ -7,8 +7,17 @@ This package contains wrappers for accessing the ALSA API from Python.
 It is fairly complete for PCM devices and Mixer access.
 """
 readme.content-type = "text/plain"
-license="PSF-2.0"
-license-files=["LICENSE"]
+
+license.file = "LICENSE"
+
+# NOTE: license as a table has been deprecated by PEP-639, however support in
+# setuptools has been introduced in v77.0 which is not installable on Python
+# 3.9. Since this project doesn't constraint the minimum python version, we have
+# to stick to the legacy `license` definition for now.
+
+# license="PSF-2.0"
+# license-files=["LICENSE"]
+
 classifiers = [
 	"Development Status :: 4 - Beta",
 	"Intended Audience :: Developers",
@@ -37,7 +46,7 @@ issues = "https://github.com/larsimmisch/pyalsaaudio/issues"
 
 
 [build-system]
-requires = ["setuptools>=80.0"]
+requires = ["setuptools"]
 build-backend = "setuptools.build_meta"
 
 
@@ -48,6 +57,13 @@ ext-modules = [
 
 
 [tool.cibuildwheel.linux]
+# Use uv and build
+build-frontend = "build[uv]"
+
+# NOTE: ensure to use the correct package manager depending on the manylinux
+# image used. For AlmaLinux based images, use `yum`, for Debian based images
+# use `apt`. `cibuildwheel` v3.1.4 defaults to manylinux_2_28, which is
+# based on AlmaLinux 8.
 before-all = "yum install -y alsa-lib-devel"