Update rejected-requests.asciidoc (#119547)

I believe this is a typo, as in our 8.16.1 cluster this field appears to be called `combined_coordinating_and_primary`

Author: IanLee1521

docs/reference/troubleshooting/common-issues/rejected-requests.asciidoc

@@ -63,7 +63,7 @@ These stats are cumulative from node startup.
 
 Indexing pressure rejections appear as an
 `EsRejectedExecutionException`, and indicate that they were rejected due
-to `coordinating_and_primary_bytes`, `coordinating`, `primary`, or `replica`.
+to `combined_coordinating_and_primary`, `coordinating`, `primary`, or `replica`.
 
 These errors are often related to <<task-queue-backlog,backlogged tasks>>,
 <<docs-bulk,bulk index>> sizing, or the ingest target's
@@ -77,4 +77,4 @@ These errors are often related to <<task-queue-backlog,backlogged tasks>>,
 
 If {es} regularly rejects requests and other tasks, your cluster likely has high
 CPU usage or high JVM memory pressure. For tips, see <<high-cpu-usage>> and
-<<high-jvm-memory-pressure>>.
+<<high-jvm-memory-pressure>>.