Describe the bug

when running the tests offline there are errors recently introduced by #8698.

Steps to reproduce the behavior

1. Build hg from this repository
2. Run make test
3. See error

Expected vs actual behavior

All the other tests are successfully passing; however, there are a few specific tests that are failing. A potential workaround involves using the command -skip="TestRunInspect|TestJSONOutput|TestNewSigstoreVerifier|TestRunVerify|TestTUFRootVerify", though this approach lacks elegance.

To address this issue more gracefully, one of two strategies could be employed: either emulate the remote call with a local one or categorize these tests as online tests so they can be selectively skipped. This could streamline the testing process while maintaining the integrity of the test suite.