fix(sign-doc): remove unused dep

Signed-off-by: bkioshn <[email protected]>

Author: bkioshn

rust/signed_doc/Cargo.toml

@@ -21,7 +21,6 @@ brotli = "7.0.0"
 ed25519-dalek = { version = "2.1.1", features = ["pem", "rand_core"] }
 uuid = { version = "1.11.0", features = ["v4", "v7", "serde"] }
 hex = "0.4.3"
-thiserror = "2.0.9"
 strum = { version = "0.26.3", features = ["derive"] }
 
 [dev-dependencies]