Fix bulk queue size in thread pool docs

This commit fixes an incorrect specification for the default queue size
for the bulk thread pool in the thread pool docs.

Relates #23870

docs/reference/modules/threadpool.asciidoc

@@ -32,7 +32,7 @@ There are several thread pools, but the important ones include:
 `bulk`::
     For bulk operations. Thread pool type is `fixed`
     with a size of `# of available processors`,
-    queue_size of `50`.  The maximum size for this pool
+    queue_size of `200`.  The maximum size for this pool
     is `1 + # of available processors`.
 
 `snapshot`::