Arch difference will generate unknown harnesses

The two harnesses in `str::pattern::verify` are unknown because dv is developed on aarch64 while kani-list.json is from amd64 machine of verify-rust-std CI.

<img width="1908" height="834" alt="Image" src="https://github.com/user-attachments/assets/66d8865d-4cc6-4ac8-9bb4-be43e92a15f9" />