Remove `import ucp` from the top of `ucx.py` (#3510)
Remove `import ucp` from the top of `ucx.py` (#3510)

This is needed to ensure Dask configurations will be propagated
to UCX upon importing. Since `ucx.py` is imported upon
`import distributed`, Dask configurations passed to
`Nanny(..., config=ucx_config)` won't be read by UCX since it has
already been loaded.
dask/distributed,dask/distributed,blaze/distributed,dask/distributed,dask/distributed,blaze/distributed