DOCS: Adjust /cat/thread_pool expectation with ccr

The fix proposed in elastic#31442 fails with the oss distro because the added
3dots does not match anything with the default oss while a 3dots
expression requires matching at least one thread pool.

This change adjusts the thread pool list so that it can match both the
oss (without ccr) and default distro (with ccr).

docs/reference/cat/thread_pool.asciidoc

@@ -16,10 +16,11 @@ Which looks like:
 --------------------------------------------------
 node-0 analyze             0 0 0
 ...
-node-0 fetch_shard_started 0 0 0
 node-0 fetch_shard_store   0 0 0
 node-0 flush               0 0 0
 ...
+node-0 search              0 0 0
+...
 node-0 write               0 0 0
 --------------------------------------------------
 // TESTRESPONSE[s/\.\.\./(node-0 \\S+ 0 0 0\n)+/]