nit: change to simpleLRU

waku/v2/protocol/peer_exchange/enr_cache.go

@@ -7,21 +7,21 @@ import (
 	"sync"
 
 	"github.com/ethereum/go-ethereum/p2p/enode"
-	lru "github.com/hashicorp/golang-lru"
+	"github.com/hashicorp/golang-lru/simplelru"
 	"github.com/waku-org/go-waku/waku/v2/protocol/peer_exchange/pb"
 )
 
-// there is Arccache which is also thread safe but it is too verbose for the use-case and adds unnecessary overhead
+// simpleLRU internal uses container/list, which is ring buffer(double linked list)
 type enrCache struct {
 	// using lru, saves us from periodically cleaning the cache to maintain a certain size
-	data *lru.Cache
+	data *simplelru.LRU
 	rng  *rand.Rand
 	mu   sync.RWMutex
 }
 
 // err on negative size
 func newEnrCache(size int) (*enrCache, error) {
-	inner, err := lru.New(size)
+	inner, err := simplelru.NewLRU(size, nil)
 	return &enrCache{
 		data: inner,
 		rng:  rand.New(rand.NewSource(rand.Int63())),