When CKEditor5 is installed, only allow SVGs for button icons

Can we not instead allow both SVG and PNG, to address the BC concern? #6 is interesting but we can't call those automatically from within Drupal. So perhaps a context-dependent validation would be appropriate: if the CKEditor 5 module is installed, trigger a validation error if Embed only has a PNG button icon and not also a SVG button icon?

Then there's zero effect for existing sites. There's a reasonable change in behavior for sites using CKEditor 5, but only an essential change.

What do you think about that middle ground, @Dave Reid?

Yeah I feel like allowing for both PNG and SVG for now is the best solution. I think we could also add a hook_requirement runtime check that if only the ckeditor5 module is enabled (and not ckeditor), that if any embed buttons do not have SVGs to add an error that it needs to be fixed. We could potentially look at writing an update hook to programatically update PNGs to SVG, but that will require a larger effort.

I can work on updating the MR to get this ready today.

I tested this out and it works great. I cloned the MR and when I went to the Status Report, I saw this output:

The D10 test failure seems to be #3190024: Problem with test dependencies when testing issue forks →

I've thoroughly been testing this and am going to merge it since it helps unblock Entity Embed and CKEditor5.

Epic turn-around time here! 🤩 Talked to @Dave Reid yesterday, and now it's already fixed 🤯

I need to make it to more events! :D

😄 When I told Megh & Tim about our encounter on the street where you informed me of this having landed, they said "THAT IS SOOOOO DAVE!" 😁

Automatically closed - issue fixed for 2 weeks with no activity.