requirements: bump min aiorpcx to 0.22.0

aiorpcx 0.20 changed the behaviour/API of TaskGroups.
When used as a context manager, TaskGroups no longer propagate
exceptions raised by their tasks. Instead, the calling code has
to explicitly check the results of tasks and decide whether to re-raise
any exceptions.
This is a significant change, and so this commit introduces "OldTaskGroup",
which should behave as the TaskGroup class of old aiorpcx. All existing
usages of TaskGroup are replaced with OldTaskGroup.

closes https://github.com/spesmilo/electrum/issues/7446

electrum/bip39_recovery.py

@@ -4,20 +4,19 @@
 
 from typing import TYPE_CHECKING
 
-from aiorpcx import TaskGroup
-
 from . import bitcoin
 from .constants import BIP39_WALLET_FORMATS
 from .bip32 import BIP32_PRIME, BIP32Node
 from .bip32 import convert_bip32_path_to_list_of_uint32 as bip32_str_to_ints
 from .bip32 import convert_bip32_intpath_to_strpath as bip32_ints_to_str
+from .util import OldTaskGroup
 
 if TYPE_CHECKING:
     from .network import Network
 
 
 async def account_discovery(network: 'Network', get_account_xpub):
-    async with TaskGroup() as group:
+    async with OldTaskGroup() as group:
         account_scan_tasks = []
         for wallet_format in BIP39_WALLET_FORMATS:
             account_scan = scan_for_active_accounts(network, get_account_xpub, wallet_format)
@@ -46,7 +45,7 @@ async def scan_for_active_accounts(network: 'Network', get_account_xpub, wallet_
 
 async def account_has_history(network: 'Network', account_node: BIP32Node, script_type: str) -> bool:
     gap_limit = 20
-    async with TaskGroup() as group:
+    async with OldTaskGroup() as group:
         get_history_tasks = []
         for address_index in range(gap_limit):
             address_node = account_node.subkey_at_public_derivation("0/" + str(address_index))