event_scrubber doesn't scrub events

### How do you use Sentry?

Sentry Saas (sentry.io)

### Version

2.29.1

### Steps to Reproduce

```python
import sentry_sdk
from sentry_sdk.scrubber import EventScrubber, DEFAULT_DENYLIST, DEFAULT_PII_DENYLIST

# custom denylist
denylist = DEFAULT_DENYLIST + ["my_sensitive_var", "color"]
pii_denylist = DEFAULT_PII_DENYLIST + ["my_private_var", "color"]

sentry_sdk.init(
dsn="MY_DSN",
send_default_pii=False,
event_scrubber=EventScrubber(denylist=denylist, pii_denylist=pii_denylist, recursive=True),
traces_sample_rate=1.0,
profile_session_sample_rate=1.0,
profile_lifecycle="trace",
)
```

### Expected Result

When visiting the app through the browser, and adding the parameter `?color=red` (ie. in my case `http://127.0.0.1:8000/polls/error/?color=red`), I would expect for it to be scrubbed in my Sentry event.

### Actual Result

The `color` parameter does not get scrubbed.

Example event from my test org [here](https://dragonfruit-us.sentry.io/issues/6655889994/?project=4504490632871936&query=is%3Aunresolved&referrer=issue-stream&stream_index=0).