contrib: support reading XORed blocks in linearize-data.py script

Partly fixes issue #30599.

test/functional/feature_loadblock.py

@@ -26,10 +26,6 @@ class LoadblockTest(BitcoinTestFramework):
         self.setup_clean_chain = True
         self.num_nodes = 2
         self.supports_cli = False
-        self.extra_args = [
-            ["-blocksxor=0"],  # TODO: The linearize scripts should be adjusted to apply any XOR
-            [],
-        ]
 
     def run_test(self):
         self.nodes[1].setnetworkactive(state=False)