Relax profiles assertions (elastic#123923) (elastic#123936)

If the final driver is woken up before the exchange buffer is finished, 
there will be two sleeps in its profile instead of one. We don't need
these assertions to be so precise. This change relaxes the assertions to
allow reduce operators to have more than one sleep.

Author: dnhatn

x-pack/plugin/esql/qa/server/single-node/src/javaRestTest/java/org/elasticsearch/xpack/esql/qa/single_node/RestEsqlIT.java

@@ -504,7 +504,7 @@ public void testForceSleepsProfile() throws IOException {
             String description = p.get("description").toString();
             switch (description) {
                 case "data" -> assertMap(sleeps, matchesMap().entry("counts", Map.of()).entry("first", List.of()).entry("last", List.of()));
-                case "node_reduce" -> {
+                case "node_reduce", "final" -> {
                     assertMap(sleeps, matchesMap().entry("counts", matchesMap().entry("exchange empty", greaterThan(0))).extraOk());
                     @SuppressWarnings("unchecked")
                     List<Map<String, Object>> first = (List<Map<String, Object>>) sleeps.get("first");
@@ -517,14 +517,6 @@ public void testForceSleepsProfile() throws IOException {
                         assertMap(s, sleepMatcher);
                     }
                 }
-                case "final" -> {
-                    assertMap(
-                        sleeps,
-                        matchesMap().entry("counts", matchesMap().entry("exchange empty", 1))
-                            .entry("first", List.of(sleepMatcher))
-                            .entry("last", List.of(sleepMatcher))
-                    );
-                }
                 default -> throw new IllegalArgumentException("unknown task: " + description);
             }
         }