Project metadata: Increase minimum Python version to say >=3.9 (#1817)

Author: amotl

Diff for: pyproject.toml

@@ -8,15 +8,14 @@ dynamic = ["version"]
 description = "File-system specification"
 readme = "README.md"
 license = { file = "LICENSE" }
-requires-python = ">=3.8"
+requires-python = ">=3.9"
 maintainers = [{ name = "Martin Durant", email = "[email protected]" }]
 keywords = ["file"]
 classifiers = [
     "Development Status :: 4 - Beta",
     "Intended Audience :: Developers",
     "License :: OSI Approved :: BSD License",
     "Operating System :: OS Independent",
-    "Programming Language :: Python :: 3.8",
     "Programming Language :: Python :: 3.9",
     "Programming Language :: Python :: 3.10",
     "Programming Language :: Python :: 3.11",