`corr` incorrect result with `NaN`

[comphead]

Describe the bug

in postgresql

select corr('nan'::float, 'nan'::float)
NaN

in DF

> select corr('nan'::float, 'nan'::float);
+-------------------------------+
| corr(Utf8("nan"),Utf8("nan")) |
+-------------------------------+
| NULL                          |
+-------------------------------+
1 row(s) fetched. 
Elapsed 0.008 seconds.

To Reproduce

No response

Expected behavior

No response

Additional context

No response