Node configured to mock mine keeps complaining about no UTXOs

[diwakergupta]

Describe the bug

I have a node configured to mock mine:

[node]
miner = true                                                                                                                                                                   │
mock_mining = true

In the logs, I see repeated WARN messages about missing UTXOs:

stacks-node[348792]: WARN [1739887644.149435] [testnet/stacks-node/src/burnchains/bitcoin_regtest_controller.rs:1707] [relayer-http://0.0.0.0:20543/] No UTXOs for 04423252e65b4219143e4b6d90608afa651511701ea6a8d08209e8db9d2c2a4aec966a0fa3d3775a54bd3e06cbbf87315b564fc9a3eea25136e5b2b71b8f9d9ee0 (1A7396ngNGn6cotfYx4VmHEWt13Cn2dyts) in epoch 3.1
stacks-node[348792]: WARN [1739887644.490545] [testnet/stacks-node/src/burnchains/bitcoin_regtest_controller.rs:1707] [relayer-http://0.0.0.0:20543/] No UTXOs for 04423252e65b4219143e4b6d90608afa651511701ea6a8d08209e8db9d2c2a4aec966a0fa3d3775a54bd3e06cbbf87315b564fc9a3eea25136e5b2b71b8f9d9ee0 (1A7396ngNGn6cotfYx4VmHEWt13Cn2dyts) in epoch 3.1
stacks-node[348792]: WARN [1739887644.882546] [testnet/stacks-node/src/burnchains/bitcoin_regtest_controller.rs:1707] [relayer-http://0.0.0.0:20543/] No UTXOs for 04423252e65b4219143e4b6d90608afa651511701ea6a8d08209e8db9d2c2a4aec966a0fa3d3775a54bd3e06cbbf87315b564fc9a3eea25136e5b2b71b8f9d9ee0 (1A7396ngNGn6cotfYx4VmHEWt13Cn2dyts) in epoch 3.1
stacks-node[348792]: WARN [1739887645.376611] [testnet/stacks-node/src/burnchains/bitcoin_regtest_controller.rs:1707] [relayer-http://0.0.0.0:20543/] No UTXOs for 04423252e65b4219143e4b6d90608afa651511701ea6a8d08209e8db9d2c2a4aec966a0fa3d3775a54bd3e06cbbf87315b564fc9a3eea25136e5b2b71b8f9d9ee0 (1A7396ngNGn6cotfYx4VmHEWt13Cn2dyts) in epoch 3.1

These logs can be confusing and misleading for node operators.

Expected behavior

The node knows it is mock mining, so it should either not check for UTXOs or not complaining about missing UTXOs.

Environment (please complete the following information):

• OS: Ubuntu
• Node: latest release (3.1.0.0.6)

Additional context
Please include any relevant stack traces, error messages and logs.

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