• [ x] Checked for duplicates

Describe the bug

Docs
When using addOwned, the collection takes ownership of the object. When called from Python, ownership remains with PyROOT, though, so there's two owners now.

A Pythonisation should be added to avoid this. It should include a call such as:
ROOT.SetOwnership(obj, False)

Expected behavior

Ownership is transferred to the collection.

To Reproduce

Something like

coll = ROOT.RooArgSet()
if True:
   x = ROOT.RooRealVar('x', 'x', -10, 10)
   coll.addOwned(x)
   # Similarly:
   coll.addOwned(ROOT.RooRealVar('y', ...))

# Now should be able to touch x in coll without problems