Add build-system to fix entry point installation (#3)

Without a [build-system] table, uv treats the project as unpackaged
and skips installing the patchwork CLI entry point. Add hatchling as
the build backend so uv sync installs the command correctly.

Author: pnilan

pyproject.toml

@@ -12,6 +12,10 @@ dependencies = [
     "pyyaml",
 ]
 
+[build-system]
+requires = ["hatchling"]
+build-backend = "hatchling.build"
+
 [project.scripts]
 patchwork = "patchwork.cli:main_cli"