Fix msu assertion in restore shard history test

Since #40249, we always reinitialize max_seq_no_of_updates to max_seq_no
when a promoting primary restores history regardless of whether it did
rollback previously or not.

Closes #40929

server/src/test/java/org/elasticsearch/index/shard/IndexShardTests.java

@@ -1092,7 +1092,6 @@ public void testGlobalCheckpointSync() throws IOException {
         closeShards(replicaShard, primaryShard);
     }
 
-    @AwaitsFix(bugUrl = "https://github.com/elastic/elasticsearch/issues/40929")
     public void testRestoreLocalHistoryFromTranslogOnPromotion() throws IOException, InterruptedException {
         final IndexShard indexShard = newStartedShard(false);
         final int operations = 1024 - scaledRandomIntBetween(0, 1024);
@@ -1147,13 +1146,8 @@ public void onFailure(Exception e) {
         assertThat(indexShard.getLocalCheckpoint(), equalTo(maxSeqNo));
         assertThat(indexShard.seqNoStats().getMaxSeqNo(), equalTo(maxSeqNo));
         assertThat(getShardDocUIDs(indexShard), equalTo(docsBeforeRollback));
-        if (shouldRollback) {
-            // we conservatively roll MSU forward to maxSeqNo during restoreLocalHistory, ideally it should become just
-            // currentMaxSeqNoOfUpdates
-            assertThat(indexShard.getMaxSeqNoOfUpdatesOrDeletes(), equalTo(maxSeqNo));
-        } else {
-            assertThat(indexShard.getMaxSeqNoOfUpdatesOrDeletes(), equalTo(Math.max(currentMaxSeqNoOfUpdates, maxSeqNoOfUpdatesOrDeletes)));
-        }
+        // we conservatively roll MSU forward to maxSeqNo during restoreLocalHistory, ideally it should become just currentMaxSeqNoOfUpdates
+        assertThat(indexShard.getMaxSeqNoOfUpdatesOrDeletes(), equalTo(maxSeqNo));
         closeShard(indexShard, false);
     }