fix(config): use bittensor logging for neuron full path in check_config

[kyan9400]

Problem

check_config printed the resolved neuron directory with print, which bypasses bt.logging and can pollute stdout for validator/miner processes.

Change

This PR replaces the raw print call with bt.logging.debug, using a clear Neuron full path: message while preserving the existing path setup behavior.

Tests

Added focused tests covering:

• check_config no longer emits the legacy full path: message to stdout/stderr.
• config.neuron.full_path is set correctly.
• The expected neuron directory is created under the configured logging root.

Testing

uv sync --extra dev
uv run ruff check gittensor/utils/config.py tests/test_config_paths.py
uv run pytest tests/test_config_paths.py -q

[kyan9400]

Hi, just checking if there is anything I should adjust here. The branch is behind test now, but GitHub shows it can still be merged cleanly. I can rebase if preferred.

[anderdc]

Drop all the tests, make this just the one-liner to move from print to bt.logging.

[anderdc]

Drop all the tests, make this just the one-liner to move from print to bt.logging.