Update curve25519-dalek requirement from =4.0.0-rc.0 to =4.0.0-rc.1

Updates the requirements on [curve25519-dalek](https://github.com/dalek-cryptography/curve25519-dalek) to permit the latest version.
- [Release notes](https://github.com/dalek-cryptography/curve25519-dalek/releases)
- [Changelog](https://github.com/dalek-cryptography/curve25519-dalek/blob/main/CHANGELOG.md)
- [Commits](https://github.com/dalek-cryptography/curve25519-dalek/commits)

---
updated-dependencies:
- dependency-name: curve25519-dalek
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

Cargo.toml

@@ -45,7 +45,7 @@ aes-gcm = { version = "0.9", optional = true }
 chacha20poly1305 = { version = "0.9", optional = true }
 blake2 = { version = "0.10", optional = true }
 sha2 = { version = "0.10", optional = true }
-curve25519-dalek = { version = "=4.0.0-rc.0", optional = true }
+curve25519-dalek = { version = "=4.0.0-rc.1", optional = true }
 
 pqcrypto-kyber = { version = "0.7", optional = true }
 pqcrypto-traits = { version = "0.3", optional = true }