Remove redundant exclusions

Setting `config.rails_report_rescued_exceptions` to `false` makes having
these exceptions in `config.excluded_exceptions` redundant.

All the exceptions present in `config.action_dispatch.rescue_responses`
can be removed from `config.excluded_exceptions`.

See
https://guides.rubyonrails.org/configuring.html#configuring-action-dispatch
for the list of exceptions in `config.action_dispatch.rescue_responses`.

Trello card: https://trello.com/c/Ik7ulDXQ/1768-3-upgrade-frontend-to-rails-6

lib/govuk_app_config/configure.rb

@@ -8,16 +8,9 @@
   config.silence_ready = !Rails.env.production? if defined?(Rails)
 
   config.excluded_exceptions = [
-    'AbstractController::ActionNotFound',
-    'ActionController::BadRequest',
-    'ActionController::InvalidAuthenticityToken',
-    'ActionController::ParameterMissing',
-    'ActionController::RoutingError',
     'ActionController::UnknownAction',
-    'ActionController::UnknownHttpMethod',
     'ActionDispatch::RemoteIp::IpSpoofAttackError',
     'ActiveJob::DeserializationError',
-    'ActiveRecord::RecordNotFound',
     'CGI::Session::CookieStore::TamperedWithCookie',
     'GdsApi::HTTPIntermittentServerError',
     'GdsApi::TimedOutException',