[BUG] datetime64[ns] columns throw exn's on umap

[lmeyerov]

Describe the bug

In g.nodes(df[['time']]).umap(), a datetime64[ns] col causes an exn

Expected behavior

No exn, either:

• natively handle datetimes
• convert to numeric and treat like that
• drop unsupported type with a warning

Actual behavior

Exn

PyGraphistry API client environment

0.25.1

Additional context

Production user