Bump lru from 0.7.8 to 0.8.0 (#6060)

* Bump lru from 0.7.8 to 0.8.0

Bumps [lru](https://github.com/jeromefroe/lru-rs) from 0.7.8 to 0.8.0.
- [Release notes](https://github.com/jeromefroe/lru-rs/releases)
- [Changelog](https://github.com/jeromefroe/lru-rs/blob/master/CHANGELOG.md)
- [Commits](https://github.com/jeromefroe/lru-rs/compare/0.7.8...0.8.0)

---
updated-dependencies:
- dependency-name: lru
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

* Change `LruCache` paramerter to `NonZeroUsize`

* Change type of `session_cache_lru_size` to `NonZeroUsize`

* Add expects instead of unwrap

Co-authored-by: Bastian Köcher <info@kchr.de>

* Use match to get rid of expects

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Sebastian Kunert <skunert49@gmail.com>
Co-authored-by: Bastian Köcher <info@kchr.de>

polkadot/node/subsystem-util/src/runtime/mod.rs

@@ -16,7 +16,7 @@
 
 //! Convenient interface to runtime information.
 
-use std::cmp::max;
+use std::num::NonZeroUsize;
 
 use lru::LruCache;
 
@@ -52,7 +52,7 @@ pub struct Config {
 	pub keystore: Option<SyncCryptoStorePtr>,
 
 	/// How many sessions should we keep in the cache?
-	pub session_cache_lru_size: usize,
+	pub session_cache_lru_size: NonZeroUsize,
 }
 
 /// Caching of session info.
@@ -95,7 +95,7 @@ impl Default for Config {
 		Self {
 			keystore: None,
 			// Usually we need to cache the current and the last session.
-			session_cache_lru_size: 2,
+			session_cache_lru_size: NonZeroUsize::new(2).expect("2 is larger than 0; qed"),
 		}
 	}
 }
@@ -109,7 +109,10 @@ impl RuntimeInfo {
 	/// Create with more elaborate configuration options.
 	pub fn new_with_config(cfg: Config) -> Self {
 		Self {
-			session_index_cache: LruCache::new(max(10, cfg.session_cache_lru_size)),
+			session_index_cache: LruCache::new(
+				cfg.session_cache_lru_size
+					.max(NonZeroUsize::new(10).expect("10 is larger than 0; qed")),
+			),
 			session_info_cache: LruCache::new(cfg.session_cache_lru_size),
 			keystore: cfg.keystore,
 		}