[ClassDiagram] Link deletion with keybord doesn't work

Step to reproduce :

1. Create a new ClassDiagram

2. Create 2 classes

3. Create an Abstraction between these classes

4. Select the Abstraction

5. Press the "Del" key on your keyboard

   1. the dialog "Are you Sure, This action will delete.... " is opened.
   2. Press "Enter" on your keybord

   Nothing happens! ...

This behavior seems to exist for all links of all diagrams...

see https://github.com/eclipse-sirius/sirius-web/issues/3507