Update Rust crate nom to v8

Author: oxide-renovate[bot]

Cargo.lock

@@ -68,7 +68,7 @@ colored = "3.0"
 ctrlc = { version = "3.4.7", features = ["termination"] }
 ztest = { git = "https://github.com/oxidecomputer/falcon", branch = "main" }
 anstyle = "1.0.11"
-nom = "7.1"
+nom = "8.0"
 num_enum = "0.7.3"
 pretty-hex = "0.4"
 pretty_assertions = "1.4"