Low accuracy for OGBn-Arxiv dataset

## ❓ Questions and Help
Hello Team,
I am conducting experiments on DGL with the ogbn-arxiv dataset. However, my test accuracy is 0.5547, which is significantly lower than the results reported on the [OGB leaderboard](https://ogb.stanford.edu/docs/leader_nodeprop/#ogbn-arxiv). Could you please provide guidance on achieving better performance?

## DGL 1.2
Experiment details:
```
Dataset : ogbn-arxiv
Sampler : Neighbor Sampler
Fanout : [10,10,10]
Batch_size : [1000]
```
Hardware details:
```
Architecture: x86_64
CPU op-mode(s): 32-bit, 64-bit
Address sizes: 48 bits physical, 48 bits virtual
Byte Order: Little Endian
CPU(s): 64
On-line CPU(s) list: 0-63
Vendor ID: AuthenticAMD
Model name: AMD EPYC 7313 16-Core Processor
CPU family: 25
Model: 1
Thread(s) per core: 2
Core(s) per socket: 16
Socket(s): 2
Stepping: 1
Frequency boost: enabled
CPU(s) scaling MHz: 45%
CPU max MHz: 3729.4919
CPU min MHz: 1500.0000
BogoMIPS: 6000.04
Virtualization: AMD-V
Caches (sum of all):
L1d: 1 MiB (32 instances)
L1i: 1 MiB (32 instances)
L2: 16 MiB (32 instances)
L3: 256 MiB (8 instances)
NUMA:
NUMA node(s): 2
NUMA node0 CPU(s): 0-15,32-47
NUMA node1 CPU(s): 16-31,48-63
```
Code used to measure accuracy
[arxiv_accuracy.txt](https://github.com/dmlc/dgl/files/15457507/arxiv_accuracy.txt)

### Output Snapshot