Chat progress messages are reported multiple times to screenreader

[roblourens]

Testing #210661

• Send a request to @workspace
• This participant shows 3 progress messages
• The screen reader reads them but they get read multiple times in random order

I'm not scrolling or anything, this is just what happens as the response renders normally. I'm assuming this is due to progress messages being re-rendered, and the screenreader hooking into the rendering flow

[meganrogge]

@roblourens I cannot reproduce (at least on macOS), I am only seeing the progress messages once and they occur when I expect them to. Can you provide a gif?

[roblourens]

They each appear once, it's just that the screenreader reads them multiple times

[meganrogge]

I don't see the screen reader reading them multiple times. Can you make a gif?

[roblourens]

It reads them once as they come in, and a second time when it reads the content of the response when the response is done. Pushing a change to not consider the progress message part of the 'content', which I think is correct since the progress messages disappear from the view once more content has loaded.

This also fixes the fact that the progress messages appear when I Copy a chat response (never noticed that before)