Setting aria-live on Etherpad's editor causes unwanted verbosity for screen reader users

[lukaszgo1]

Describe the bug Since merge of #5149 aria-live is incorrectly set on the Etherpad's editor causing annoying verbosity for users of the NVDA screen reader - each entered character is repeated unnecessarily.

To Reproduce

1. Start NVDA and Firefox Nightly
2. Go to any Etherpad instance - I've tested with both https://rich.etherpad.com/ and the instance hosted at https://pad.chapril.org/
3. Go to the editor, ensure that keyboard echo in NVDA is disabled (this can either by done with keyboard shortcut NVDA+2 or in preferences -> Settings -> Keyboard settings)
4. Start typing
5. Notice that each entered character is unnecessarily spoken

Expected behavior Entered characters should not be echoed back, since user disabled the keyboard echo.

Screenshots Not applicable

Desktop (please complete the following information):

• OS: Windows 10 X64
• Browser Firefox Nightly
• Version 112

Additional context This issue has been introduced in #5149 by @vwbij to fix some issue with JAWS. Unfortunately they didn't provide a clear steps to reproduce the original problem, so it is impossible to suggest a solution. Adding aria-live to the edit field is however certainly a misuse of the attribute and should not be done. Also CC @rhansen since you've reviewed the original PR.