DEV: Remove the use of Capybara::Session#quit (#24978)

Why this change?

This is what `Capybara::Session#quit` does:

```
    def quit
      @driver.quit if @driver.respond_to? :quit
      @document = @driver = nil
      @touched = false
      @server&.reset_error!
    end
```

One notable thing is that it resets server errors which means that any
server errors encountered by a session is cleared. That is not what we
want since it hides errors even though `Capybara.raise_server_errors`
has been set to `true`.

plugins/chat/spec/system/edited_message_spec.rb

@@ -23,12 +23,11 @@ RSpec.describe "Edited message", type: :system do
       it "shows as edited for all users" do
         chat_page.visit_channel(channel_1)
 
-        using_session(:user_1) do |session|
+        using_session(:user_1) do
           sign_in(editing_user)
           chat_page.visit_channel(channel_1)
           channel_page.edit_message(message_1, "a different message")
           expect(page).to have_content(I18n.t("js.chat.edited"))
-          session.quit
         end
 
         expect(page).to have_content(I18n.t("js.chat.edited"))