Replace EllipsoidalSet doc for np.float with ...

Author: jas-yao

pyomo/contrib/pyros/uncertainty_sets.py

@@ -2844,7 +2844,7 @@ class EllipsoidalSet(UncertaintySet):
            [0, 0, 3, 0],
            [0, 0, 0, 4]])
     >>> conf_ellipsoid.scale
-    np.float64(9.4877...)
+    ...9.4877...
     >>> conf_ellipsoid.gaussian_conf_lvl
     0.95