Merge pull request #1203 from kenkoooo/dependabot/cargo/atcoder-problems-backend/rand-0.8.4

build(deps): bump rand from 0.7.3 to 0.8.4 in /atcoder-problems-backend

Author: kenkoooo

atcoder-problems-backend/Cargo.lock

@@ -10,7 +10,7 @@ publish = false
 log = "0.4"
 fern = "0.6.1"
 
-rand = "0.7.3"
+rand = "0.8.4"
 chrono = "0.4"
 regex = "1"
 rust-s3 = { version = "0.27.0-rc4", features = ["no-verify-ssl"] }