fix: use the newer preferred method for error comparison in tests

[Justintime50]

Description

Per the docs, this new method of error comparison is preferred, let's follow best practice: https://pkg.go.dev/errors (bottom)

Testing

Pull Request Type

Please select the option(s) that are relevant to this PR.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Improvement (fixing a typo, updating readme, renaming a variable name, etc.)