fix(code): Don't write sarif files when no results are found

[PeterSchafer]

Pull Request Submission Checklist

• Follows CONTRIBUTING guidelines
• Includes detailed description of changes
• Contains risk assessment (Low | Medium | High)
• Highlights breaking API changes (if applicable)
• Links to automated tests covering new functionality
• Includes manual testing instructions (if necessary)
• Updates relevant GitBook documentation (PR link: ___)

What does this PR do?

This PR implements the same behavior for the golang native code test as the legacy implementation, when scanning a code base without findings and using --sarif-file-output. The expected behavior based on the legacy implementation is, that if there are no code test findings, the sarif file is not created at all.

The risk of the change is low, since currently the only affected flow is code test.

Where should the reviewer start?

The main functionality is implemented here snyk/go-application-framework#304

This PR just configures the output workflow and re-enables a test for the golang native implementation, that previously failed due to the difference in behavior.

How should this be manually tested?

Run snyk code test --sarif-file-output=myfile on a code base

1. with findings => myfile is created
2. without findings => myfile is not created