Remove deprecation silencing in debug exceptions

This was added in 9a27b297 to silence
warnings about deprecated instance variables, see
https://discuss.rubyonrails.org/t/internal-api-errors-in-edgerails/6082
for more details.

The deprecations that it was silencing were removed in
83c8db98.

actionpack/lib/action_dispatch/middleware/debug_exceptions.rb

@@ -139,16 +139,14 @@ def log_error(request, wrapper)
         exception = wrapper.exception
         trace = wrapper.exception_trace
 
-        ActiveSupport::Deprecation.silence do
-          message = []
-          message << "  "
-          message << "#{exception.class} (#{exception.message}):"
-          message.concat(exception.annotated_source_code) if exception.respond_to?(:annotated_source_code)
-          message << "  "
-          message.concat(trace)
-
-          log_array(logger, message)
-        end
+        message = []
+        message << "  "
+        message << "#{exception.class} (#{exception.message}):"
+        message.concat(exception.annotated_source_code) if exception.respond_to?(:annotated_source_code)
+        message << "  "
+        message.concat(trace)
+
+        log_array(logger, message)
       end
 
       def log_array(logger, array)