When editing a post, hide or disable things that cannot be changed. #30
Description
There are a few things that cannot be changed, per the Mastodon API, when editing a post. The most known one of these is visibility, you're initial visibility is stuck unless you delete and redraft the post. We also just discovered that language might potentially be one of these as well, or perhaps that's merely a mastodon.py limitation. In either case, it's not practically editable.
Right now when editing a post, these settings show up just as they do for a new post and still act as if they function, but actually do nothing. Editing a direct post and changing it to unlisted, for example, sends and even plays the normal send sound, but the post is still shown as direct on the web. Your app is also known to simply discard the language setting.
My suggestion, therefore, is to take one of two paths. Either completely hide these unchangeable settings when editing, or else show them but make them read-only, so they show as visible indicators of state of the post but cannot be changed. If done properly screen readers would indicate their unavailable status, I believe NVDA says unavailable and VoiceOver says dimmed.
Given the choice between the two I'd probably pick the disabling one so long as it behaves properly with all the screen readers and platforms you support.