We were getting a deprecation warning after upgrading to Rails 7.1:
```
DEPRECATION WARNING: Setting action_dispatch.show_exceptions to true is
deprecated. Set to :all instead.
```
So we're passing `:all`.
I've checked whether we can remove the `:show_exceptions` tag completely
now that the new default option is `:rescuable`. The answer is "no" ;).
Removing the `:show_exceptions` tag makes the tests fail.
f5221536a9