[AWS] Remove PAT token and secrets modules

[JDBraun]

These modules have been involved with SRA since it's start:

• https://github.com/databricks/terraform-databricks-sra/blob/main/aws/tf/modules/sra/databricks_workspace/workspace_security_modules/secret_management/secret_management.tf
• https://github.com/databricks/terraform-databricks-sra/blob/main/aws/tf/modules/sra/databricks_workspace/workspace_security_modules/token_management/token_management.tf

However, these are the only modules that aren't optional, so folks are automatically looped into these. They are so simple, that these shouldn't be hard to introduce if need be.

[jdbraun-db]

updated with #94 both modules have been removed