setup: add pydantic-core constraint for Python 3.13+ compatibility (#43575) (#43595)

* setup: add pydantic-core constraint for Python 3.13+ compatibility

pydantic-core < 2.20 ships no pre-built wheels for cp313 and
attempts to build from source using PyO3 0.21.x which does not
support Python 3.13+, causing bootstrap to fail.

Add a version-gated constraint so pip resolves a compatible
pydantic-core when running on Python >= 3.13.

* suggestion from gemini

Author: shubhamdp

scripts/setup/constraints.txt

@@ -292,3 +292,7 @@ setuptools==68.0.0
 # Higher versions depend on proto-plus, which break
 # nanopb code generation (due to name conflict of the 'proto' module)
 google-api-core==2.17.0
+
+# pydantic-core < 2.20 uses PyO3 0.21.x which does not support Python 3.13+
+# See: https://github.com/pydantic/pydantic/issues/11524
+pydantic-core>=2.20.0,<3.0.0; python_version >= "3.13"