chore(deps): bump the cargo group across 2 directories with 1 update (#8)

Bumps the cargo group with 1 update in the /vext directory: [rand](https://github.com/rust-random/rand).
Bumps the cargo group with 1 update in the /vext-email-gateway/fuzz directory: [rand](https://github.com/rust-random/rand).


Updates `rand` from 0.8.5 to 0.8.6
- [Release notes](https://github.com/rust-random/rand/releases)
- [Changelog](https://github.com/rust-random/rand/blob/0.8.6/CHANGELOG.md)
- [Commits](rust-random/rand@0.8.5...0.8.6)

Updates `rand` from 0.8.5 to 0.8.6
- [Release notes](https://github.com/rust-random/rand/releases)
- [Changelog](https://github.com/rust-random/rand/blob/0.8.6/CHANGELOG.md)
- [Commits](rust-random/rand@0.8.5...0.8.6)

---
updated-dependencies:
- dependency-name: rand
  dependency-version: 0.8.6
  dependency-type: indirect
  dependency-group: cargo
- dependency-name: rand
  dependency-version: 0.8.6
  dependency-type: indirect
  dependency-group: cargo
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

vext-email-gateway/Cargo.lock

@@ -24,7 +24,7 @@ ed25519-dalek = { version = "2.1", features = ["rand_core"] }     # Ed25519 sign
 sha2 = "0.10"             # SHA-256 (NIST standard)
 blake3 = "1.5"            # BLAKE3 (faster, also secure)
 hex = "0.4"
-rand = "0.9"
+rand = "0.10"
 
 # Serialization (proven)
 serde = { version = "1.0", features = ["derive"] }