src/sage/interfaces/singular.py: remove nonsense OUTPUT block

It looks like the OUTPUT block for singular_version() was copy/pasted
from somewhere else -- it doesn't make sense. We delete it; the
remaining short description of this function is sufficient.

src/sage/interfaces/singular.py

@@ -2486,11 +2486,6 @@ def singular_version():
     """
     Return the version of Singular being used.
 
-    OUTPUT:
-
-    A string describing the Singular function ``name``. A ``KeyError``
-    is raised if no such function was found in the Singular documentation.
-
     EXAMPLES::
 
         sage: singular.version()