pw_ring_buffer: Add missing includes

This file uses limits header but didn't include it before.

Change-Id: I4c727accc31dcbe3f8e79249c71bfe6bfbd07ce6
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/115490
Pigweed-Auto-Submit: Dennis Kormalev <denk@google.com>
Reviewed-by: Rob Mohr <mohrr@google.com>
Commit-Queue: Auto-Submit <auto-submit@pigweed.google.com.iam.gserviceaccount.com>

Author: dkormalev

pw_ring_buffer/public/pw_ring_buffer/prefixed_entry_ring_buffer.h

@@ -14,6 +14,7 @@
 #pragma once
 
 #include <cstddef>
+#include <limits>
 
 #include "pw_containers/intrusive_list.h"
 #include "pw_result/result.h"