script, test: fix python linter E275 errors with flake8 5.0.4

test/functional/wallet_avoidreuse.py

@@ -195,7 +195,7 @@ class AvoidReuseTest(BitcoinTestFramework):
         # getbalances should show no used, 10 btc trusted
         assert_balances(self.nodes[1], mine={"used": 0, "trusted": 10})
         # node 0 should not show a used entry, as it does not enable avoid_reuse
-        assert("used" not in self.nodes[0].getbalances()["mine"])
+        assert "used" not in self.nodes[0].getbalances()["mine"]
 
         self.nodes[1].sendtoaddress(retaddr, 5)
         self.generate(self.nodes[0], 1)