Fix docs on error conditions in LeafVersion::from_consensus

Author: dr-orlovsky

src/util/taproot.rs

@@ -820,7 +820,6 @@ impl LeafVersion {
     /// # Errors
     /// - If the last bit of the `version` is odd.
     /// - If the `version` is 0x50 ([`TAPROOT_ANNEX_PREFIX`]).
-    /// - If the `version` is not a valid [`LeafVersion`] byte.
     // Text from BIP341:
     // In order to support some forms of static analysis that rely on
     // being able to identify script spends without access to the output being