fix: include docs and examples in the sdist tarball

The sdists generated by setuptools included the `docs` and `examples`
directories, and they are needed for building docs and running tests using the
sdist.

This change includes these directories in the sdist tarball.

A `test:sdist` task is also added to `Taskfile.yml` which uses the sdists to run
pytest and build docs.

Taskfile.yml

@@ -218,6 +218,8 @@ tasks:
       - task: venv:clean
       - task: _rimraf
         vars: { RIMRAF_TARGET: ".var/devcontainer" }
+      - task: _rimraf
+        vars: { RIMRAF_TARGET: "var/test-sdist" }
 
   test:data:fetch:
     desc: Fetch test data.
@@ -342,6 +344,21 @@ tasks:
               > "${plantuml_file%.*}.svg"
           done
 
+  test:sdist:
+    desc: Run tests on the sdist artifact
+    cmds:
+      - task: _rimraf
+        vars: { RIMRAF_TARGET: "dist" }
+      - task: _rimraf
+        vars: { RIMRAF_TARGET: "var/test-sdist" }
+      - poetry build
+      - python -c 'import tarfile, glob; tarfile.open(glob.glob("dist/*.tar.gz")[0]).extractall("var/test-sdist")'
+      - |
+        cd var/test-sdist/rdflib-*
+        poetry install
+        poetry run mypy --show-error-context --show-error-codes -p rdflib
+        poetry run sphinx-build -T -W -b html -d docs/_build/doctree docs docs/_build/html
+        poetry run pytest
   _rimraf:
     # This task is a utility task for recursively removing directories, it is
     # similar to rm -rf but not identical and it should work wherever there is

pyproject.toml

@@ -27,6 +27,8 @@ packages = [
 ]
 include = [
     { path = "test", format = "sdist" },
+    { path = "docs", format = "sdist" },
+    { path = "examples", format = "sdist" },
 ]
 
 [tool.poetry.scripts]