Reverts #3689 and #3738 back to the original working codebase

[martinRenou]

Reverts #3689 and #3738

As discussed in #3735. We should probably revert those in a patch release, then be back with a solution that works nicely later.

[github-actions]

👈 Launch a binder notebook on branch jupyter-widgets/ipywidgets/revert-3689-patch-1

[martinRenou]

meeseeksdev please backport to 7.x

[lumberbot-app]

Owee, I'm MrMeeseeks, Look at me.

There seem to be a conflict, please backport manually. Here are approximate instructions:

1. Checkout backport branch and update it.

git checkout 7.x
git pull

2. Cherry pick the first parent branch of the this PR on top of the older branch:

git cherry-pick -x -m1 2c76d22d688d3b61b65a08dd0046df0c4a65ea77

3. You will likely have some merge/cherry-pick conflict here, fix them and commit:

git commit -am 'Backport PR #3830: Reverts #3689 and #3738 back to the original working codebase'

4. Push to a named branch:

git push YOURFORK 7.x:auto-backport-of-pr-3830-on-7.x

5. Create a PR against branch 7.x, I would have named this PR:

"Backport PR #3830 on branch 7.x (Reverts #3689 and #3738 back to the original working codebase)"

And apply the correct labels and milestones.

Congratulations — you did some good work! Hopefully your backport PR will be tested by the continuous integration and merged soon!

Remember to remove the Still Needs Manual Backport label once the PR gets merged.

If these instructions are inaccurate, feel free to suggest an improvement.