## Bug description

There seems to be an issue with `get_available_timezones_with_offsets`, not sure at what point it broke.

```
Traceback (most recent call last):
    response = view_func(request, *args, **kwargs)
  File "/posthog/posthog/views.py", line 184, in preflight_check
    "available_timezones": get_available_timezones_with_offsets(),
    raise NonExistentTimeError(dt)
```

## Expected behavior
Preflight should work and the timezone list be returned correctly.


## How to reproduce

1. Just check `/_preflight` request

## Environment

- [X] PostHog Cloud
- [ ] self-hosted PostHog, version/commit: _please provide_

## Additional context

Tagging @Twixes as you have more context on this.

#### *Thank you* for your bug report – we love squashing them!

posthog/utils.py
if not data:
        return None
    
    with push_scope() as scope:
        scope.set_context("data", data)
    compression = (
        request.GET.get("compression") or request.POST.get("compression") or request.headers.get("content-encoding", "")
    )
    compression = compression.lower()
    if compression == "gzip" or compression == "gzip-js":
        data = gzip.decompress(data)
    if compression == "lz64":
        if isinstance(data, str):
            data = lzstring.LZString().decompressFromBase64(data.replace(" ", "+"))
        else:
            data = lzstring.LZString().decompressFromBase64(data.decode().replace(" ", "+"))
        data = data.encode("utf-16", "surrogatepass").decode("utf-16")
    
    try:
        
        
        
        data = json.loads(data, parse_constant=lambda x: None)
    except json.JSONDecodeError:
        
        data = base64_to_json(data)
    data_res["data"] = data
    
    return data_res
class SingletonDecorator: