Warning prompt when installing Elementor Beta

### What

A warning prompt when activating Elementor Beta (and potentially other beta software) with language similar to this:

> It looks like you are trying to install beta software on your site. Please note that beta software is known to cause problems as it has not been fully tested and may break your site or cause unexpected issues. It may not break your site right away but these plugins tend to update regularly and may randomly cause problems. It is strongly recommended that you do not install beta software on your site unless you are ok with features breaking and are familiar with beta software.
> `Cancel installation` | `Install anyways`

### Why

I have seen an increase in contacts related to sites breaking as a direct result of Elementor Beta. Users do not seem to understand that this is beta software, meaning that it may be buggy or break their site entirely. Adding a warning would help inform users of this so that they understand the risks of beta software and do not show up in chat upset because their site unexpectedly breaks.

Here are two interactions from today alone:
37643981-hc
29812797-hc

### How

I think a confirmation popup would be the best way to do it, but it could also be a warning added to the plugins page.

The issue names no files, tests, or entry points. Start by locating the Elementor Beta activation flow and existing plugin-install confirmation UI; done means a warning presents the stated risks with Cancel installation and Install anyways actions, while clarifying whether the prompt applies to other beta software.

Written by the indexing model from the issue text.