tests: Add test scenario for IM34DT05 digital microphone.

[nedseb]

Add a YAML test scenario file tests/scenarios/im34dt05.yaml for the IM34DT05 driver.

Expected tests

• Mock: verify driver initialization
• Hardware: read audio samples, verify PDM data capture
• Manual: validate microphone captures sound

Reference

• Driver: lib/im34dt05/
• Test framework: PR tests: add test framework with mock and hardware support. #28

Blocked by

• im34dt05: Add driver for digital microphone. #45 — Driver must be implemented first.