elliptic-curve: use base16ct::mixed in FromStr impl for ScalarValue (#2037)

Closes #1643

Author: newpavlov

elliptic-curve/CHANGELOG.md

@@ -7,8 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## 0.14.0 (UNRELEASED)
 ### Changed
 - Edition changed to 2024 and MSRV bumped to 1.85 ([#1759])
+- Accept mixed-case hex-encoded strings in `FromStr` impl for `ScalarValue` ([#2037])
 
 [#1759]: https://github.com/RustCrypto/traits/pull/1759
+[#2037]: https://github.com/RustCrypto/traits/pull/2037
 
 ## 0.13.8 (2023-11-18)
 ### Changed

elliptic-curve/src/scalar/value.rs

@@ -396,7 +396,7 @@ where
 
     fn from_str(hex: &str) -> Result<Self> {
         let mut bytes = FieldBytes::<C>::default();
-        base16ct::lower::decode(hex, &mut bytes)?;
+        base16ct::mixed::decode(hex, &mut bytes)?;
         Self::from_slice(&bytes)
     }
 }