`test_non_ostree` failure race condition?

From the [packit PR](https://src.fedoraproject.org/rpms/bootc/pull-request/14) -> [aarch64 build log](https://kojipkgs.fedoraproject.org//work/tasks/3194/129773194/build.log)

```
failures:
---- test_non_ostree stdout ----
thread 'test_non_ostree' panicked at ostree-ext/tests/it/main.rs:1337:5:
assertion `left == right` failed
left: Digest { algorithm: Sha256, value: "sha256:898c9219d1a94659edb77a7fc8cfb9c1b23dcab3bd2f4c74c9b618d9dd979d2f", split: 6 }
right: Digest { algorithm: Sha256, value: "sha256:3d56a2320917879cfa94425fbba9120bad584b07ecf4722be03652865f6cf6cc", split: 6 }
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
failures:
test_non_ostree
test result: FAILED. 25 passed; 1 failed; 1 ignored; 0 measured; 0 filtered out; finished in 2.75s
error: test failed, to rerun pass `-p ostree-ext --test it`
```