fix(saluki-common): adapt cache lifecycle to quick_cache 0.7

quick_cache 0.7 removed Lifecycle::begin_request in favor of
constructing RequestState via Default, which broke the build.

Author: jszwedko

lib/saluki-common/src/cache/expiry.rs

@@ -259,9 +259,6 @@ where
 {
     type RequestState = ();
 
-    #[inline]
-    fn begin_request(&self) -> Self::RequestState {}
-
     #[inline]
     fn on_evict(&self, _state: &mut Self::RequestState, key: K, _value: V) {
         // Note: this fires for all capacity-driven evictions including rejected overweight