test: Remove unused unnamed parameter from block.serialize call

All blocks and transactions are serialized with witness, no need to set
this

Author: MarcoFalke

test/functional/feature_taproot.py

@@ -1218,7 +1218,7 @@ def block_submit(self, node, txs, msg, err_msg, cb_pubkey=None, fees=0, sigops_w
         witness and add_witness_commitment(block)
         block.rehash()
         block.solve()
-        block_response = node.submitblock(block.serialize(True).hex())
+        block_response = node.submitblock(block.serialize().hex())
         if err_msg is not None:
             assert block_response is not None and err_msg in block_response, "Missing error message '%s' from block response '%s': %s" % (err_msg, "(None)" if block_response is None else block_response, msg)
         if (accept):