Stop creating unnecessary arrays in Renderer._updateAttrs

[sunesimonsen]

This PR optimizes the Renderer._updateAttrs by removing a unnecessary Array.from call.

This change is a bit more controversial than my previous changes as it changes the order of iterations. I believe the semantics to be identical, but it should be reviewed with a bit of extra care.

[scofalik]

Thanks for this suggestion! We plan to include it in the October CKEditor 5 release.

It wasn't clear to me why you needed to change the order - it shouldn't matter. But there was a test failing and after debugging I realized that attributes are sometimes renamed as they are set on DOM due to unsafe attributes handling. Hence, it is important to remove first, and set second, as the other way around we would remove an attribute that was just set.

I'll add a comment as this is not obvious at the first glance.

[sunesimonsen]

It wasn't clear to me why you needed to change the order - it shouldn't matter. But there was a test failing and after debugging I realized that attributes are sometimes renamed as they are set on DOM due to unsafe attributes handling. Hence, it is important to remove first, and set second, as the other way around we would remove an attribute that was just set.

Yes it was to avoid the test failure.

[scofalik]

Introduced in #17144.

[niegowski]

Unfortunately, we had to partially revert this line as it caused issues removing multiple attributes as attributes is a live collection.
The fix: https://github.com/ckeditor/ckeditor5/pull/17489/files

[sunesimonsen]

Sorry about that.