[REV] web: revert wrong fix on popper reposition

This reverts commit 38b689bb.

The IntersectionObserver strategy it implements do not
fullfil properly its purpose.
It was a mistake trying to use this kind of observer as
it is specifically meant for a different use case than
the one we tried to solve in the first place.

Another fix should follow directly this revert commit.

X-original-commit: 690f7b94
Part-of: odoo/odoo#125359