[Firefox] Deletion of expanded range causes the editor to crash

[clauderic]

Description
There was a regression introduced in Firefox by #4529 which causes the editor to crash when deleting an expanded range that spans across more than a single node.

Recording

Firefox.expanded.selection.crash.mp4

Steps
To reproduce the behavior:

1. Select an expanded range that spans across more than a single node
2. Press deletet
3. Editor crashes

Environment

• Browser: Any version of Firefox (tested in Firefox 92, 91 and 90)

[nemanja-tosic]

Introduced by #4529. Namely, i wanted to be smart and have only one event.preventDefault(), but missed an early return so it wasn't called for delete on an expanded selection. PR coming shortly.

[nemanja-tosic]

@clauderic could you test #4549 please