Bump rand from 0.6.4 to 0.6.5 (#2564)

* Bump rand from 0.6.4 to 0.6.5

Bumps [rand](https://github.com/rust-random/rand) from 0.6.4 to 0.6.5.
- [Release notes](https://github.com/rust-random/rand/releases)
- [Changelog](https://github.com/rust-random/rand/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rust-random/rand/compare/0.6.4...0.6.5)

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

* Update rand_core, rand_jitter, rand_os

fixes compile errors due to type mismatch from differing versions

metrics/Cargo.toml

@@ -17,7 +17,7 @@ sys-info = "0.5.6"
 solana-sdk = { path = "../sdk", version = "0.12.0" }
 
 [dev-dependencies]
-rand = "0.6.4"
+rand = "0.6.5"
 
 [lib]
 name = "solana_metrics"