[!813] Use std::move(yArray) to not implicitly copy array.

Merge branch 'fix/use-std-move-to-not-copy-array-implicitly' into 'master'

See merge request [!813]

  [!813]: Nonecore/dune-common/merge_requests/813

dune/python/common/vector.hh

@@ -270,7 +270,7 @@ namespace Dune
           getFixedTensor( xi, x, i );
           setFixedTensor( f( xi ), y, i );
         }
-        return yArray;
+        return std::move(yArray);
       }
       else
         throw pybind11::value_error( "Tensor has too many dimensions" );