Prevent changes to closed Issues and Milestones

First. I'm not good at English. please excuse me. 😓

I've used a project management site like a gitlab in my company. That site does not contents edit "Closed" Issue.

Further details

"Closed" is End(or Finish). Issue and Milestone must complete the contents edit before "Closed".

Proposal

• Disable some editable buttons in "Closed" Issue page

• Disable some Editable control in Closed" Milestone page