[3.1][UI] Create Bridge and Bond buttons grayed out where they should not be

[webteam-app]

Bug originally filed by alanbach at https://bugs.launchpad.net/bugs/1977661

This is a minor UI quirk and will be great if can be fixed. Here is some details to reproduce. I tested with a machine that has 2 NICs:

• Go to MAAS UI, pick a machine.
• Go to Network tab, select both interfaces, then click "Create Bond".
• Create and save the bond.
• Delete the bond that was just created.
• "Create Bond" button remains greyed out, where it should get re-enabled after the bond was deleted.

The exact same issue happens to "Create Bridge" button:

• Go to MAAS UI, pick a machine.
• Go to Network tab, select both interfaces, then click "Create Bond".
• Create and save the bond.
• Select the bond, then click "Create Bridge".
• Create and save the bridge.
• Delete the bridge that was just created.
• "Create Bridge" button remains greyed out, where it should get re-enabled after the bridge was deleted.

Please let me know if you have any questions.

Thank you, Alan