feat: Add earthfile for vit-testing | NPG-0000

[kukkok3]

Description

Adding a earthfile to vit-testing. This is needed to enable the build of backend artifacts in the catalyst-artifacts repo

Type of change

Please delete options that are not relevant.

• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

Runned on my local machine

Checklist

• [x ] My code follows the style guidelines of this project
• [x ] I have performed a self-review of my code
• [x ] I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• [x ] My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules