TEST: Avoid merges in testSeqNoAndCheckpoints

Since LUCENE-8263, testSeqNoAndCheckpoints might trigger merges because
of the updates and deletes in the test. Our merge scheduler will trigger
a flush if there is no pending merge. Those extra flushes will change
the last committed segmentInfos in the engine and fail the test.

This commit uses LogMergePolicy for the engine in the test to avoid
merges.

Closes #32430

server/src/test/java/org/elasticsearch/index/engine/InternalEngineTests.java

@@ -2024,7 +2024,6 @@ public void testIndexWriterInfoStream() throws IllegalAccessException, IOExcepti
         }
     }
 
-    @AwaitsFix(bugUrl = "https://github.com/elastic/elasticsearch/issues/32430")
     public void testSeqNoAndCheckpoints() throws IOException {
         final int opCount = randomIntBetween(1, 256);
         long primarySeqNo = SequenceNumbers.NO_OPS_PERFORMED;
@@ -2034,10 +2033,12 @@ public void testSeqNoAndCheckpoints() throws IOException {
         long replicaLocalCheckpoint = SequenceNumbers.NO_OPS_PERFORMED;
         final long globalCheckpoint;
         long maxSeqNo = SequenceNumbers.NO_OPS_PERFORMED;
+        IOUtils.close(store, engine);
+        store = createStore();
         InternalEngine initialEngine = null;
 
         try {
-            initialEngine = engine;
+            initialEngine = createEngine(defaultSettings, store, createTempDir(), newLogMergePolicy(), null);
             final ShardRouting primary = TestShardRouting.newShardRouting("test", shardId.id(), "node1", null, true,
                 ShardRoutingState.STARTED, allocationId);
             final ShardRouting replica = TestShardRouting.newShardRouting(shardId, "node2", false, ShardRoutingState.STARTED);
@@ -2053,7 +2054,7 @@ public void testSeqNoAndCheckpoints() throws IOException {
                     // we have some docs indexed, so delete one of them
                     id = randomFrom(indexedIds);
                     final Engine.Delete delete = new Engine.Delete(
-                        "test", id, newUid(id), SequenceNumbers.UNASSIGNED_SEQ_NO, 0,
+                        "test", id, newUid(id), SequenceNumbers.UNASSIGNED_SEQ_NO, primaryTerm.get(),
                         rarely() ? 100 : Versions.MATCH_ANY, VersionType.INTERNAL, PRIMARY, 0);
                     final Engine.DeleteResult result = initialEngine.delete(delete);
                     if (result.getResultType() == Engine.Result.Type.SUCCESS) {
@@ -2070,7 +2071,7 @@ public void testSeqNoAndCheckpoints() throws IOException {
                     id = randomFrom(ids);
                     ParsedDocument doc = testParsedDocument(id, null, testDocumentWithTextField(), SOURCE, null);
                     final Engine.Index index = new Engine.Index(newUid(doc), doc,
-                        SequenceNumbers.UNASSIGNED_SEQ_NO, 0,
+                        SequenceNumbers.UNASSIGNED_SEQ_NO, primaryTerm.get(),
                         rarely() ? 100 : Versions.MATCH_ANY, VersionType.INTERNAL,
                         PRIMARY, 0, -1, false);
                     final Engine.IndexResult result = initialEngine.index(index);