remove warning filter

Tests were unable to produce a situation
where the filtered warning could be produced.
The goal was to add a more specific filter
(one that uses a message). If the warning
can be reproduced the filter with a message
can be re-added. It's possible this warning
is no longer produced and so this commit
removes the filter.

src/stcal/outlier_detection/utils.py

@@ -325,10 +325,7 @@ def _reproject(x, y):
         flat_sky = []
         for axis in sky:
             flat_sky.append(axis.flatten())
-        # Filter out RuntimeWarnings due to computed NaNs in the WCS
-        with warnings.catch_warnings():
-            warnings.simplefilter("ignore", RuntimeWarning)
-            det = backward_transform(*tuple(flat_sky))
+        det = backward_transform(*tuple(flat_sky))
         det_reshaped = []
         for axis in det:
             det_reshaped.append(axis.reshape(x.shape))