auth: CredentialsProviderError "profile did not contain credential_process"

# Problem

Reported on marketplace reviews (2024-02-27):

> authenticating a connection, it always gives an error `Error: Unable to authenticate connection -> CredentialsProviderError: Profile did not contain credential_process` even though it definitely *does* contain a `credential_process` and literally every other AWS tool works happily with my AWS SSO configuration.

# Expected behavior

Handle more `credential_process` variations.

Start by reproducing the connection-authentication failure with an AWS SSO configuration containing credential_process variations, comparing the result with other AWS tools. Done means the connection authenticates successfully for the reported credential_process forms, including the marketplace-reported profile case.

Written by the indexing model from the issue text.