chore: adhere to ruff's RUF rules, 2nd try (#2420)

* chore: adhere to ruff's `RUF` rules, 2nd try
closes #2382

tests/wallets/fixtures/models.py

@@ -120,7 +120,7 @@ class WalletTest(BaseModel):
                 self.dict()
                 | {
                     "description": f"""{self.description}:{mock.description or ""}""",
-                    "mocks": self.mocks + [mock],
+                    "mocks": [*self.mocks, mock],
                     "skip": self.skip or mock.skip,
                 }
             )

tests/wallets/helpers.py

@@ -1,5 +1,7 @@
+import functools
 import importlib
 import json
+import operator
 from typing import Dict, List
 
 import pytest
@@ -24,7 +26,9 @@ def wallet_fixtures_from_json(path) -> List["WalletTest"]:
             fn_tests = _tests_for_function(funding_sources, fn_name, fn)
             _merge_dict_of_lists(tests, fn_tests)
 
-        all_tests = sum([tests[fs_name] for fs_name in tests], [])
+        all_tests: list["WalletTest"] = functools.reduce(
+            operator.iadd, [tests[fs_name] for fs_name in tests], []
+        )
         return all_tests