setuptools → flit

Also:
- Write package version to `_version.py` instead of `version.py`.
- Get rid of the `README` symlink, `README.md` is good enough nowadays.
- I have deliberately removed from the sdist: hidden files, `HOWTOPUBLISH` and `benchmark`.

Author: DimitriPapadopoulos

HOWTOPUBLISH

@@ -3,12 +3,12 @@ python -m pre_commit run -a # and then commit changes
 tox -e py310-extra,py311-extra,py312-extra,py313-extra,py314-extra
 # tag version release (vX.Y.Z)
 python -m pip install build twine
-python -m build -s # this will update tabulate/version.py
+python -m build -s # this will update tabulate/_version.py
 python -m pip install . # install tabulate in the current venv
 python -m pip install -r benchmark/requirements.txt
 python benchmark/benchmark.py  # then update README
 # move tag to the last commit
-python -m build -s # update tabulate/version.py
+python -m build -s # update tabulate/_version.py
 python -m build -nswx .
 git push # wait for all CI builds to succeed
 git push --tags # if CI builds succeed

MANIFEST.in

@@ -1,6 +1,6 @@
 [build-system]
-requires = ["setuptools>=77.0.3", "setuptools_scm[toml]>=3.4.3"]
-build-backend = "setuptools.build_meta"
+requires = ["flit>=3.12", "flit_scm"]
+build-backend = "flit_scm:buildapi"
 
 [project]
 name = "tabulate"
@@ -32,7 +32,12 @@ widechars = ["wcwidth>=0.6.0"]
 [project.scripts]
 tabulate = "tabulate:_main"
 
+[tool.flit.sdist]
+include = ["CHANGELOG", "test/", "tox.ini"]
+exclude = ["tabulate/_version.py"]
+
 [tool.setuptools_scm]
+write_to = "tabulate/_version.py"
 
 [dependency-groups]
 dev = [
@@ -45,6 +50,7 @@ dev = [
 
 [tool.ruff]
 line-length = 99
+exclude = ["tabulate/_version.py"]
 
 [tool.ruff.lint]
 extend-select = ["W", "ISC", "I", "C90"]