Update libtest-mimic requirement from 0.7.0 to 0.8.1 (#860)

Updates the requirements on [libtest-mimic](https://github.com/LukasKalbertodt/libtest-mimic) to permit the latest version.
- [Release notes](https://github.com/LukasKalbertodt/libtest-mimic/releases)
- [Changelog](https://github.com/LukasKalbertodt/libtest-mimic/blob/master/CHANGELOG.md)
- [Commits](LukasKalbertodt/libtest-mimic@v0.7.0...v0.7.3)

---
updated-dependencies:
- dependency-name: libtest-mimic
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Cargo.toml

@@ -59,7 +59,7 @@ digest = { version = "0.10", default-features = false }
 hashbrown = { version = "0.14", default-features = false, features = ["inline-more", "allocator-api2"] }
 hex = "0.4"
 itertools = { version = "0.13", default-features = false }
-libtest-mimic = "0.7.0"
+libtest-mimic = "0.8.1"
 paste = "1.0"
 rayon = "1"
 serde = "1.0"