test(eth): fix execution/inclusion off-by-one

StateSearchMsg returns the tipset in which the message was executed to
make it easier to get receipts, the state root, etc. But the ETH API
cares about the inclusion tipset.

itests/eth_conformance_test.go

@@ -504,12 +504,15 @@ func waitForMessageWithEvents(ctx context.Context, t *testing.T, client *kit.Tes
 	require.NoError(t, err)
 	require.NotNil(t, msgHash)
 
-	ts, err := client.ChainGetTipSet(ctx, ret.TipSet)
+	executionTs, err := client.ChainGetTipSet(ctx, ret.TipSet)
 	require.NoError(t, err)
 
-	blockNumber := ethtypes.EthUint64(ts.Height())
+	inclusionTs, err := client.ChainGetTipSet(ctx, executionTs.Parents())
+	require.NoError(t, err)
+
+	blockNumber := ethtypes.EthUint64(inclusionTs.Height())
 
-	tsCid, err := ts.Key().Cid()
+	tsCid, err := inclusionTs.Key().Cid()
 	require.NoError(t, err)
 
 	blockHash, err := ethtypes.EthHashFromCid(tsCid)