Cannot use S3 bucket for database export

**Problem**

The documentation states you can use either `gcp` or `s3` for CUBEJS_DB_EXPORT_BUCKET_TYPE: https://cube.dev/docs/product/configuration/reference/environment-variables#cubejs_db_export_bucket_type

Yet, when setting value to s3 along with other necessary env variables:
```
CUBEJS_DB_EXPORT_BUCKET_TYPE=s3
CUBEJS_DB_EXPORT_BUCKET=some-bucket-name
CUBEJS_DB_EXPORT_BUCKET_AWS_KEY=xxx
CUBEJS_DB_EXPORT_BUCKET_AWS_SECRET=yyy
CUBEJS_DB_EXPORT_BUCKET_AWS_REGION=zzz
```

I am getting following error after running a query using preaggregation:
```
The CUBEJS_DB_EXPORT_BUCKET_TYPE must be one of the [gcp].
```

Running latest (as of this moment) v1.6 official docker images.

Is s3 supported then or not?

Thank you

**Related Cube.js schema**
N/A

**Related Cube.js generated SQL**
N/A