chore: update more dependencies (#145)

* update more dependencies

* cargo fmt

* address review comments

* fix format

src/group/mod.rs

@@ -18,7 +18,7 @@ use digest::core_api::BlockSizeUser;
 use digest::{FixedOutput, HashMarker};
 use generic_array::typenum::{IsLess, IsLessOrEqual, Sum, U256};
 use generic_array::{ArrayLength, GenericArray};
-use rand_core::{CryptoRng, RngCore};
+use rand_core::{TryCryptoRng, TryRngCore};
 #[cfg(feature = "ristretto255")]
 pub use ristretto::Ristretto255;
 use subtle::{Choice, ConstantTimeEq};
@@ -100,8 +100,11 @@ where
     /// is not a valid point on the group or the identity element.
     fn deserialize_elem(element_bits: &[u8]) -> Result<Self::Elem>;
 
-    /// picks a scalar at random
-    fn random_scalar<R: RngCore + CryptoRng>(rng: &mut R) -> Self::Scalar;
+    /// Picks a scalar at random.
+    ///
+    /// # Errors
+    /// [`Error::Rng`](crate::Error::Rng) if the random number generator fails.
+    fn random_scalar<R: TryRngCore + TryCryptoRng>(rng: &mut R) -> Result<Self::Scalar>;
 
     /// The multiplicative inverse of this scalar
     fn invert_scalar(scalar: Self::Scalar) -> Self::Scalar;