Cherry-pick: fix invalid python_version target in cuda_core/pixi.toml

Cherry-picked from PR #2029 (commit 18f5a02) to unblock pixi install.
Pixi's [package.target.<X>] only accepts platform identifiers; the
'python_version < "3.11"' selector caused parse failures.

Co-authored-by: Keith Kraus <kkraus14@users.noreply.github.com>

Author: cursoragent

cuda_core/pixi.lock

@@ -185,8 +185,10 @@ cuda-version = "*"
 numpy = "*"
 cuda-bindings = "*"
 cuda-pathfinder = "*"
-
-[package.target.'python_version < "3.11"'.run-dependencies]
+# Conda-forge ships per-Python variants of backports.strenum (real impl on
+# <3.11, no-op stub on >=3.12); pixi-build doesn't accept PEP 508-style
+# `python_version` selectors in [package.target.<X>], so list it
+# unconditionally and let the solver pick the right variant.
 "backports.strenum" = "*"
 
 [target.linux.tasks.build-cython-tests]