itest: remove unnecessary channel close and node shutdown

Since we don't have standby nodes anymore, we don't need to close the
channels when the test finishes. Previously we would do so to make sure
the standby nodes have a clean state for the next test case, which is no
longer relevant.

itest/lnd_channel_balance_test.go

@@ -63,10 +63,6 @@ func testChannelBalance(ht *lntest.HarnessTest) {
 
 	// Ensure Bob currently has no available balance within the channel.
 	checkChannelBalance(bob, 0, amount-lntest.CalcStaticFee(cType, 0))
-
-	// Finally close the channel between Alice and Bob, asserting that the
-	// channel has been properly closed on-chain.
-	ht.CloseChannel(alice, chanPoint)
 }
 
 // testChannelUnsettledBalance will test that the UnsettledBalance field
@@ -208,7 +204,4 @@ func testChannelUnsettledBalance(ht *lntest.HarnessTest) {
 	// balance that equals to the amount of invoices * payAmt. The local
 	// balance remains zero.
 	checkChannelBalance(carol, 0, aliceLocal, numInvoices*payAmt, 0)
-
-	// Force and assert the channel closure.
-	ht.ForceCloseChannel(alice, chanPointAlice)
 }