Remove transaction from updateCapacityForHost cal (apache#12421)

Author: abh1sar

server/src/main/java/com/cloud/alert/AlertManagerImpl.java

@@ -313,13 +313,8 @@ protected void recalculateHostCapacities() {
                 Math.min(CapacityManager.CapacityCalculateWorkers.value(), hostIds.size())));
         for (Long hostId : hostIds) {
             futures.put(hostId, executorService.submit(() -> {
-                Transaction.execute(new TransactionCallbackNoReturn() {
-                    @Override
-                    public void doInTransactionWithoutResult(TransactionStatus status) {
-                        final HostVO host = hostDao.findById(hostId);
-                        _capacityMgr.updateCapacityForHost(host);
-                    }
-                });
+                final HostVO host = hostDao.findById(hostId);
+                _capacityMgr.updateCapacityForHost(host);
                 return null;
             }));
         }