Merge branch 'master' into glitch-soc/merge-upstream

Conflicts:
- app/controllers/admin/base_controller.rb
  Some refactoring made upstream, no real conflict.
- app/javascript/mastodon/features/compose/components/compose_form.js
  Updated using upstream's code but using maxChars instead of the
  hardcoded length of 500 characters per toot.
- app/javascript/styles/mastodon/components.scss
  Upstream redesigned the onboarding modal. Not sure why we had a
  conflict there.

lib/mastodon/accounts_cli.rb

@@ -309,8 +309,8 @@ module Mastodon
       end
 
       old_key = account.private_key
-      new_key = OpenSSL::PKey::RSA.new(2048).to_pem
-      account.update(private_key: new_key)
+      new_key = OpenSSL::PKey::RSA.new(2048)
+      account.update(private_key: new_key.to_pem, public_key: new_key.public_key.to_pem)
       ActivityPub::UpdateDistributionWorker.perform_in(delay, account.id, sign_with: old_key)
     end
   end