PyYAML is not an actual use-time/runtime dependency of our bindings. It
is necessary only if someone wants to regenerate
`LinalgNamedStructuredOps.yaml`:
93097b2d47/mlir/tools/mlir-linalg-ods-gen/update_core_linalg_named_ops.sh.in (L29)
This PR does the minimal refactor to remove the need during actual run/use time.