internal/quic: use slices.Equal in TestAcksSent

The module go.mod uses go 1.18 and acks_test.go has a go:build go1.21
tag.

Change-Id: Ic0785bcb4795bedecc6a752f5e67a967851237e6
Reviewed-on: https://go-review.googlesource.com/c/net/+/565137
Reviewed-by: Than McIntosh <thanm@google.com>
Auto-Submit: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Jonathan Amsterdam <jba@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

internal/quic/acks_test.go

diff --git a/internal/quic/acks_test.go b/internal/quic/acks_test.go
index 4f10329..d10f917 100644
--- a/internal/quic/acks_test.go
+++ b/internal/quic/acks_test.go
@@ -7,6 +7,7 @@
 package quic
 
 import (
+	"slices"
 	"testing"
 	"time"
 )
@@ -198,7 +199,7 @@
 				if len(gotNums) == 0 {
 					wantDelay = 0
 				}
-				if !slicesEqual(gotNums, test.wantAcks) || gotDelay != wantDelay {
+				if !slices.Equal(gotNums, test.wantAcks) || gotDelay != wantDelay {
 					t.Errorf("acks.acksToSend(T+%v) = %v, %v; want %v, %v", delay, gotNums, gotDelay, test.wantAcks, wantDelay)
 				}
 			}
@@ -206,20 +207,6 @@
 	}
 }
 
-// slicesEqual reports whether two slices are equal.
-// Replace this with slices.Equal once the module go.mod is go1.17 or newer.
-func slicesEqual[E comparable](s1, s2 []E) bool {
-	if len(s1) != len(s2) {
-		return false
-	}
-	for i := range s1 {
-		if s1[i] != s2[i] {
-			return false
-		}
-	}
-	return true
-}
-
 func TestAcksDiscardAfterAck(t *testing.T) {
 	acks := ackState{}
 	now := time.Now()