Only use explicit crate features (#306)

src/envelope.rs

@@ -35,11 +35,7 @@ const STR_PRIVATE_KEY: [u8; 10] = *b"PrivateKey";
 const STR_OPAQUE_DERIVE_AUTH_KEY_PAIR: [u8; 24] = *b"OPAQUE-DeriveAuthKeyPair";
 type NonceLen = U32;
 
-#[cfg_attr(
-    feature = "serde",
-    derive(serde::Deserialize, serde::Serialize),
-    serde(crate = "serde")
-)]
+#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
 #[derive(Clone, Debug, Eq, Hash, Ord, PartialEq, PartialOrd, ZeroizeOnDrop)]
 pub(crate) enum InnerEnvelopeMode {
     Zero = 0,
@@ -73,7 +69,7 @@ impl TryFrom<u8> for InnerEnvelopeMode {
 #[cfg_attr(
     feature = "serde",
     derive(serde::Deserialize, serde::Serialize),
-    serde(bound = "", crate = "serde")
+    serde(bound = "")
 )]
 #[derive_where(Clone, Debug, Eq, Hash, Ord, PartialEq, PartialOrd, ZeroizeOnDrop)]
 pub(crate) struct Envelope<CS: CipherSuite>