Add note that workflow must be named publish-to-pypi

Co-Authored-By: Dongdong Tian <[email protected]>

Author: weiji14

.github/workflows/publish-to-pypi.yml

@@ -1,4 +1,6 @@
 # Publish archives to PyPI and TestPyPI using GitHub Actions
+# Important: this workflow filename must be publish-to-pypi.yml to match the
+# settings in PyPI and TestPyPI so that OIDC publishing works
 
 name: Publish to PyPI