[pylint] Also reports case np.nan/case math.nan (PLW0177) (#16378)

## Summary

Resolves #16374.

`PLW0177` now also reports the pattern of a case branch if it is an
attribute access whose qualified name is that of either `np.nan` or
`math.nan`.

As the rule is in preview, the changes are not preview-gated.

## Test Plan

`cargo nextest run` and `cargo insta test`.

crates/ruff_linter/resources/test/fixtures/pylint/nan_comparison.py

@@ -53,6 +53,18 @@ import builtins
 if x == builtins.float("nan"):
     pass
 
+# https://github.com/astral-sh/ruff/issues/16374
+match number:
+    # Errors
+    case np.nan: ...
+    case math.nan: ...
+
+    # No errors
+    case np.nan(): ...
+    case math.nan(): ...
+    case float('nan'): ...
+    case npy_nan: ...
+
 # OK
 if math.isnan(x):
     pass