## 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
return bool(re.match(ANONYMOUS_REGEX, distinct_id))
def mask_email_address(email_address: str) -> str:
    """
    Grabs an email address and returns it masked in a human-friendly way to protect PII.
        Example: testemail@posthog.com -> t********l@posthog.com
    """
    index = email_address.find("@")
    if index == -1:
        raise ValueError("Please provide a valid email address.")
    if index == 1:
        
        return f"*{email_address[index:]}"
    return f"{email_address[0]}{'*' * (index - 2)}{email_address[index-1:]}"
def is_valid_regex(value: Any) -> bool:
    try:
        re.compile(value)
        return True
    except re.error:
        return False
def get_absolute_path(to: str) -> str:
    """
    Returns an absolute path in the FS based on posthog/posthog (back-end root folder)
    """
    return os.path.join(__location__, to)
class GenericEmails: