Drop setuptools (again)

Author: AA-Turner

Diff for: MANIFEST.in

@@ -1,6 +1,6 @@
 [build-system]
-requires = ["setuptools>=64"]
-build-backend = "setuptools.build_meta"
+requires = ["flit_core>=3.7"]
+build-backend = "flit_core.buildapi"
 
 # project metadata
 [project]
@@ -56,8 +56,20 @@ lint = [
 name = "Georg Brandl"
 email = "[email protected]"
 
-[tool.setuptools.dynamic]
-version.attr = "sphinxcontrib.applehelp.__version__"
+[tool.flit.module]
+name = "sphinxcontrib.applehelp"
+
+[tool.flit.sdist]
+include = [
+    "CHANGES",
+    "LICENSE",
+    # Tests
+    "tests/",
+    "tox.ini",
+]
+exclude = [
+    "doc/_build",
+]
 
 [tool.mypy]
 ignore_missing_imports = true