Fix discovery integration tests

Author: zilm13

networking/p2p/src/testFixtures/java/tech/pegasys/teku/network/p2p/DiscoveryNetworkFactory.java

@@ -130,6 +130,7 @@ public DiscoveryNetwork<?> buildAndStart() throws Exception {
                               throw new UnsupportedOperationException();
                             })
                         .gossipTopicFilter(topic -> true)
+                        .timeProvider(StubTimeProvider.withTimeInMillis(0))
                         .build())
                 .peerPools(peerPools)
                 .peerSelectionStrategy(peerSelectionStrategy)