* Remove the Lib/test/imghdrdata/ directory.
* Copy 5 pictures (gif, png, ppm, pgm, xbm) from removed
Lib/test/imghdrdata/ to a new Lib/test/tkinterdata/ directory.
* Update Sphinx from 4.5 to 6.2 in Doc/requirements.txt.
* Move Lib/tkinter/test/test_tkinter/ to Lib/test/test_tkinter/.
* Move Lib/tkinter/test/test_ttk/ to Lib/test/test_ttk/.
* Add Lib/test/test_ttk/__init__.py based on test_ttk_guionly.py.
* Add Lib/test/test_tkinter/__init__.py
* Remove old Lib/test/test_tk.py.
* Remove old Lib/test/test_ttk_guionly.py.
* Add __main__ sub-modules.
* Update imports and update references to rename files.