Feature request: Add milliseconds to log timestamps

### What problem are you trying to solve?

Currently the logs show timestamps with 'second' precision. It would provide much better feedback if we could get the milliseconds as well.

### Describe the solution you'd like

Currently the timestamp looks like this:

```
13/09/2023, 18:11:50
```
I'd like to see this instead:
```
13/09/2023, 18:11:50.523
```

### Describe alternatives you've considered

You can add a timestamp to the log message yourself, but this just creates noise in the logs having two timestamps.

### Documentation, Adoption, Migration Strategy

_No response_

No implementation file, test, or entry point is identified in the issue. Start by locating the code that formats Deno Deploy log timestamps and check how the existing timestamp format is tested. Done means log timestamps include milliseconds in the requested format without requiring a second timestamp.

Written by the indexing model from the issue text.