Update pyproject.toml

update version to 4.2.1

Author: hwu36

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "nvidia-cutlass"
-version = "4.2.0.0"
+version = "4.2.1.0"
 description = "CUTLASS"
 readme = "README.md"
 requires-python = ">=3.8"