Revert "gh-116946: fully implement GC protocol for _tkinter.Tk{app,tt}Object (#138331)"

[ZeroIntensity]

This reverts commit 283380a.

#138331 caused a regression noted at #138789. We'll reapply this with a correct fix later (probably at the sprints).

• Issue: Heap types implemented in C must have Py_TPFLAGS_HAVE_GC and implement tp_traverse #116946

[picnixz]

If this is simply git revert, you can go ahead and merge it. Thank you!