snowflake_utils -- support unencrypted keys #3637

Is your feature request related to a problem? Please describe.

• snowflake_utils requires the key be encrypted. See line 88-91 of snowflake_utils
• This should be optional to support unencrypted keys

Describe the solution you'd like

• Update line 88-91 of snowflake_utils of snowflake_utils: Change to kwargs.get('private_key_passphrase') with default None
• Update line 514 of snowflake_utils parse_private_key_path to private_key_passphrase: Optional[str] = None. Handle case of unencrypted keys in function.

Describe alternatives you've considered

Additional context

I know that encrypted keys are recommended, but the Snowflake docs describe both encrypted and unencrypted keys, so ideally feast would support unencrypted keys.