pyproject.toml: clarify build system version (#634)

adamjstewart · web-flow · commit 6ff80c54cdce · 2021-12-22T11:07:01.000-06:00
diff --git a/pyproject.toml b/pyproject.toml
@@ -1,5 +1,5 @@
 [build-system]
-requires = ["jupyter_packaging~=0.9,<2"]
+requires = ["jupyter_packaging~=0.9"]
 build-backend = "jupyter_packaging.build_api"
 
 [tool.jupyter-packaging.builder]
