[FEATURE] support private key in Athena snowflake connector

[sivasankarig]

Is your feature request related to a problem? If yes, please describe.
As per the AWS documentation Athena supports only username and password for authentication , while using Athena snowflake connector
[+] https://docs.aws.amazon.com/athena/latest/ug/connectors-snowflake.html

Describe the solution you'd like
Request to add support for RSA private key, as Snowflake will block single factor password authentication by Nov 2025.
[+] https://www.snowflake.com/en/blog/blocking-single-factor-password-authentification/

Describe alternatives you've considered
While Glue snowflake connector has pem_private_key, Athena will also need similar support.

[+] https://docs.aws.amazon.com/glue/latest/dg/aws-glue-programming-etl-connect-snowflake-home.html