### Apache Airflow Provider(s)

snowflake

### Versions of Apache Airflow Providers

Versions 2.2.x (since https://github.com/apache/airflow/commit/0a37be3e3cf9289f63f1506bc31db409c2b46738).


### Apache Airflow version

2.2.1

### Operating System

Debian GNU/Linux 10 (buster)

### Deployment

Other 3rd-party Helm chart

### Deployment details

Bitnami Airflow Helm chart @ version 8.0.2

### What happened

When connecting to Snowflake via SQLAlchemy using the Snowflake Hook, I get an error that the URL is not valid because my Snowflake instance is in US West 2 (Oregon) which means I don't provide a region explicitly. Snowflake's documentation says:
> If the account is located in the AWS US West (Oregon) region, no additional segments are required and the URL would be xy12345.snowflakecomputing.com

The error is that `xy12345..snowflakecomputing.com` is not a valid URL (note the double-dot caused by the lack of a region).

### What you expected to happen

I expect the connection to be successful.

### How to reproduce

You can use the default snowflake connection if you have one defined and see this problem with the following one-liner:
```shell
python -c 'from airflow.providers.snowflake.hooks.snowflake import SnowflakeHook; SnowflakeHook().get_sqlalchemy_engine().connect()'
```

### Anything else

Fortunately I imagine the fix for this is just to leave the region URL component out when `region` is `None` here: https://github.com/apache/airflow/commit/0a37be3e3cf9289f63f1506bc31db409c2b46738#diff-2b674ac999a5b938fe5045f6475b0c5cc76e4cab89174ac448a9e1d41a5c04d5R215.

Using version `2.1.1` of the Snowflake provider with version `2.2.1` of Airflow is currently a viable workaround so for now I am just avoiding the update to the provider.

### Are you willing to submit PR?

- [ ] Yes I am willing to submit a PR!

### Code of Conduct

- [X] I agree to follow this project's [Code of Conduct](https://github.com/apache/airflow/blob/main/CODE_OF_CONDUCT.md)

airflow/providers/snowflake/hooks/snowflake.py
:param warehouse: name of snowflake warehouse
    :type warehouse: Optional[str]
    :param database: name of snowflake database
    :type database: Optional[str]
    :param region: name of snowflake region
    :type region: Optional[str]
    :param role: name of snowflake role
    :type role: Optional[str]
    :param schema: name of snowflake schema
    :type schema: Optional[str]
    :param session_parameters: You can set session-level parameters at
        the time you connect to Snowflake
    :type session_parameters: Optional[dict]
    :param insecure_mode: Turns off OCSP certificate checks.
        For details, see: `How To: Turn Off OCSP Checking in Snowflake Client Drivers - Snowflake Community
        <https://community.snowflake.com/s/article/How-to-turn-off-OCSP-checking-in-Snowflake-client-drivers>`__
    :type insecure_mode: Optional[bool]
    .. note::
        get_sqlalchemy_engine() depends on snowflake-sqlalchemy
    .. seealso::
        For more information on how to use this Snowflake connection, take a look at the guide:
        :ref:`howto/operator:SnowflakeOperator`
    """
    conn_name_attr = 'snowflake_conn_id'
    default_conn_name = 'snowflake_default'
    conn_type = 'snowflake'
    hook_name = 'Snowflake'
    supports_autocommit = True
    @staticmethod
    def get_connection_form_widgets() -> Dict[str, Any]: