build: bump rand to 0.10 and rcgen to 0.14

`rand` 0.8 -> 0.10 (skips 0.9): we only call `rand::random::<i32>()`,
which kept its API across both major bumps; no source change needed.

`rcgen` 0.13 -> 0.14 (dev-dep, used by `tls.rs` tests):
`CertifiedKey::key_pair` was renamed to `signing_key`. One-line fix
in the `self_signed_pem` test helper.

`cargo outdated --root-deps-only` now reports "All dependencies are up
to date". All 196 unit tests pass; clippy clean; reuse lint compliant.

Author: lfrancke

Cargo.lock

@@ -24,15 +24,15 @@ async-stream = "0.3"
 sqlparser = { version = "0.61", features = ["visitor"] }
 rustls-pemfile = "2"
 rustls-pki-types = "1"
-rand = "0.8"
+rand = "0.10"
 
 [build-dependencies]
 chrono = "0.4"
 
 [dev-dependencies]
 tokio-postgres = "0.7"
 tempfile = "3"
-rcgen = "0.13"
+rcgen = "0.14"
 
 [lints.clippy]
 unwrap_in_result = "deny"

Cargo.toml

@@ -95,7 +95,7 @@ mod tests {
     /// Generate a throwaway self-signed cert+key as PEM strings.
     fn self_signed_pem() -> (String, String) {
         let cert = rcgen::generate_simple_self_signed(vec!["gateway.test".to_owned()]).unwrap();
-        (cert.cert.pem(), cert.key_pair.serialize_pem())
+        (cert.cert.pem(), cert.signing_key.serialize_pem())
     }
 
     #[test]