eth, les: fix flaky tests (#20897)

* les: fix flaky test

* eth: fix flaky test

eth/handler_test.go

@@ -615,7 +615,7 @@ func testBroadcastBlock(t *testing.T, totalPeers, broadcastExpected int) {
 		case <-doneCh:
 			received++
 
-		case <-time.After(100 * time.Millisecond):
+		case <-time.After(time.Second):
 			if received != broadcastExpected {
 				t.Errorf("broadcast count mismatch: have %d, want %d", received, broadcastExpected)
 			}

les/peer_test.go

@@ -140,7 +140,7 @@ func TestHandshake(t *testing.T) {
 			if err != nil {
 				t.Fatalf("handshake failed, %v", err)
 			}
-		case <-time.NewTimer(100 * time.Millisecond).C:
+		case <-time.After(time.Second):
 			t.Fatalf("timeout")
 		}
 	}