Restructure to include py.typed end exclude junk from sdist

Author: cjw296

.github/workflows/ci.yml

@@ -137,7 +137,7 @@ jobs:
         run: uv sync --dev
 
       - name: Run tests
-        run: uv run mypy pytest_sqlalchemy.py tests
+        run: uv run mypy src tests
 
   formatting:
     runs-on: ubuntu-latest

pyproject.toml

@@ -40,13 +40,17 @@ docs = [
 ]
 
 [build-system]
-requires = ["setuptools>=61.0"]
-build-backend = "setuptools.build_meta"
+requires = ["hatchling"]
+build-backend = "hatchling.build"
 
 [tool.coverage.run]
 source = ["pytest_sqlalchemy", "tests"]
 parallel = true
 
+[tool.hatch.build.targets.sdist]
+# paranoidly only include the package in the sdist: https://github.com/pypa/hatch/issues/304
+packages = ["src/pytest_sqlalchemy"]
+
 [tool.mypy]
 disallow_untyped_defs = true
 disallow_incomplete_defs = true