Remove hasAncestor test from Python tests.
Remove hasAncestor test from Python tests.

MichaelClerx/libcellml,hsorby/libcellml,hsorby/libcellml,MichaelClerx/libcellml,cellml/libcellml,nickerso/libcellml,hsorby/libcellml,cellml/libcellml,nickerso/libcellml,MichaelClerx/libcellml,nickerso/libcellml,hsorby/libcellml,nickerso/libcellml,cellml/libcellml,cellml/libcellml