fix(logging): Reduce noise from expected InvalidSearchQuery errors in trace metrics

[sentry]

The validate_trace_metrics_aggregate function in src/sentry/search/eap/trace_metrics/validator.py was using logger.exception when catching an InvalidSearchQuery exception. This led to Sentry capturing error events for expected user input validation failures (e.g., incorrect field types in aggregate functions).

This change replaces logger.exception with logger.warning. This prevents these expected, handled validation errors from creating noisy Sentry issues, while still logging the event for debugging purposes if needed.

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Fixes SENTRY-5S5V

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