test: speedup wallet_listtransactions by whitelisting peers (immediate tx relay)

By whitelisting the peers via -whitelist, the inventory is transmissioned
immediately rather than on average every 5 seconds, speeding up the test by at
least a factor of two:

before:
$ time ./wallet_listtransactions.py
...
0m40.25s real     0m01.74s user     0m01.70s system

with this PR:
$ time ./wallet_listtransactions.py
...
0m14.93s real     0m01.68s user     0m01.87s system

This commit also moves the wallet_listtransactions tests into the < 30s group.

Author: theStack

test/functional/test_runner.py

@@ -109,8 +109,6 @@
     'p2p_tx_download.py',
     'mempool_updatefromblock.py',
     'wallet_dump.py --legacy-wallet',
-    'wallet_listtransactions.py --legacy-wallet',
-    'wallet_listtransactions.py --descriptors',
     'feature_taproot.py --previous_release',
     'feature_taproot.py',
     'rpc_signer.py',
@@ -159,6 +157,8 @@
     'wallet_createwallet.py --legacy-wallet',
     'wallet_createwallet.py --usecli',
     'wallet_createwallet.py --descriptors',
+    'wallet_listtransactions.py --legacy-wallet',
+    'wallet_listtransactions.py --descriptors',
     'wallet_watchonly.py --legacy-wallet',
     'wallet_watchonly.py --usecli --legacy-wallet',
     'wallet_reorgsrestore.py',

test/functional/wallet_listtransactions.py

@@ -18,6 +18,9 @@
 class ListTransactionsTest(BitcoinTestFramework):
     def set_test_params(self):
         self.num_nodes = 2
+        # This test isn't testing txn relay/timing, so set whitelist on the
+        # peers for instant txn relay. This speeds up the test run time 2-3x.
+        self.extra_args = [["[email protected]"]] * self.num_nodes
 
     def skip_test_if_missing_module(self):
         self.skip_if_no_wallet()