Update

pyproject.toml

@@ -19,3 +19,11 @@ classifiers = [
     "Programming Language :: Python :: 3.12"
 ]
 keywords = ["api", "json", "json-rpc", "rpc"]
+
+[build-system]
+requires = ["flit_core >=3.2,<4"]
+build-backend = "flit_core.buildapi"
+
+[tool.flit.sdist]
+include = []
+exclude = []