Force Poetry setup file (#271)

Author: cretz

pyproject.toml

@@ -20,6 +20,12 @@ exclude = ["temporalio/bridge/**/target"]
 # support this script in a subdirectory like scripts/.
 [tool.poetry.build]
 script = "build.py"
+# In https://github.com/python-poetry/poetry-core/pull/318, Poetry stopped using
+# a setup file, but we are using setuptools Rust manually in our build.py which
+# needs a setup file.
+# TODO(cretz): Find a way to not require a setup file since that is going away
+# at some point in Poetry. Revisit Maturin or fine some other approach.
+generate-setup-file = true
 
 [tool.poetry.urls]
 "Bug Tracker" = "https://github.com/temporalio/sdk-python/issues"