Remove serde-cbor dependency

Cargo.toml

@@ -51,7 +51,7 @@ sha2 = { version = "0.10", default-features = false }
 cosey = "0.3"
 delog = "0.1.0"
 cbor-smol = "0.4"
-heapless-bytes = { version = "0.3.0", features = ["cbor"] }
+heapless-bytes = { version = "0.3.0" }
 interchange = "0.3.0"
 littlefs2 = "0.4.0"
 p256-cortex-m4 = { version = "0.1.0-alpha.6", features = ["prehash", "sec1-signatures"] }
@@ -64,8 +64,6 @@ serial_test = { version = "2" }
 entropy = "0.4.0"
 once_cell = "1.13.0"
 serde_test = "1"
-# If this is not enabled, serde_test makes serde_cbor's compilation fail
-serde_cbor = { version = "0.11.2", features = ["std"] }
 trussed-derive = { path = "derive" }
 # Somehow, this is causing a regression.
 # rand_core = { version = "0.5", features = ["getrandom"] }