fix: testnet/backend prod mac mismatch

[just-a-node]

Description

Type of change

• [ ] Docs change / dependency upgrade
• [x] Configuration / tooling changes
• [ ] Refactoring
• [ ] 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 change)
• [ ] Requires changes in customer code

High-level change(s) description - from the user's perspective

Related Issue(s)

Fixes

Related pull request(s)

[preethamr]

Merge CI will not test sanity of secrets...just mine :P