tests: Use explicit imports

test/functional/feature_pruning.py

@@ -10,7 +10,8 @@ This test takes 30 mins or more (up to 2 hours)
 """
 
 from test_framework.test_framework import BitcoinTestFramework
-from test_framework.util import *
+from test_framework.util import assert_equal, assert_greater_than, assert_raises_rpc_error, connect_nodes, mine_large_block, sync_blocks, wait_until
+
 import os
 
 MIN_BLOCKS_TO_KEEP = 288