"ExecutionEngine went offline" log when shutting down process

### Describe the bug

In some cases when shutting down beacon node process it will print out the following log

```
Jul-17 18:28:42.463[] info: Syncing - 1.9 hours left - 2.67 slots/s - slot: 6091943 - head: 6073759 0xfd22…0bc1 - exec-block: valid(9347841 0xb848…) - finalized: 0x71e4…4afd:189803 - peers: 11
^CJul-17 18:28:45.061[] info: Stopping gracefully, use Ctrl+C again to force process exit
Jul-17 18:28:46.792[execution] error: ExecutionEngine went offline
```

### Expected behavior

No error log indicating that EL went of offline.

Possible fix might be to just check if process is aborted and not print out any execution client state changes.

### Steps to reproduce

Start and then shutdown beacon node once it start syncing

```sh
./lodestar beacon \
--dataDir /home/devops/goerli/data/beacon \
--metrics \
--execution.urls http://localhost:8551 \
--jwt-secret /home/devops/goerli/data/jwtsecret \
--logLevel info \
--network goerli \
--checkpointSyncUrl "https://beaconstate-goerli.chainsafe.io/"
```

This does not happen all the time, multiple tries are required. I guess it just depends on timing.

### Additional context

Related PR that introduced change
- https://github.com/ChainSafe/lodestar/pull/5723

**Further considerations**

We might also not wanna print out "ExecutionEngine" as this is quite technical term, would be better in terms of UX to just print out "Execution client" as users should be more familiar with this term.

### Operating system

Linux

### Lodestar version or commit hash

22d7cc88bf1b64a8cb4d726e57c5c313fafecd98