fix: Repair failing config integration test

[Leo10Gama]

Why is this change necessary?

One of the integration tests for sam deploy was failing when being passed an invalid config file. This is due to the fact that, when given an invalid config file, it throws a different error. This change has been better reflected in this test.

Mandatory Checklist

PRs will only be reviewed after checklist is complete

• Add input/output type hints to new functions/methods
• Write design document if needed (Do I need to write a design document?)
• Write/update unit tests
• Write/update integration tests
• Write/update functional tests if needed
• make pr passes
• make update-reproducible-reqs if dependencies were changed
• Write documentation

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.