fix: use uv_build backend for old-python-constraint-project (#729)

The test-no-python-version test was failing because hatchling's
dependency on pathspec was incompatible with Python 3.9,
causing a TypeError during the build process.

Fixed by switching from hatchling to uv_build backend
(0.9.22-0.10.0 range) which is fully compatible with
Python 3.9. The uv.lock file is updated to reflect the
new build backend and latest compatible versions of dependencies.

Author: eifinger

__tests__/fixtures/old-python-constraint-project/pyproject.toml

@@ -9,5 +9,5 @@ dependencies = [
 ]
 
 [build-system]
-requires = ["hatchling"]
-build-backend = "hatchling.build"
+requires = ["uv_build>=0.9.22,<0.10.0"]
+build-backend = "uv_build"