test: makes timeout a forced named argument in tests methods that use it

This makes calls to such methods more explicit and less error prone

test/functional/p2p_node_network_limited.py

@@ -137,7 +137,7 @@ class NodeNetworkLimitedTest(BitcoinTestFramework):
 
         self.log.info("Requesting block at height 2 (tip-289) must fail (ignored).")
         node.send_getdata_for_block(blocks[0])  # first block outside of the 288+2 limit
-        node.wait_for_disconnect(5)
+        node.wait_for_disconnect(timeout=5)
         self.nodes[0].disconnect_p2ps()
 
         # connect unsynced node 2 with pruned NODE_NETWORK_LIMITED peer