[Workflow] Fix the QEMU tests to detect a wider variety of failures, and fix the ESP32 platform manager issues that catches.

[bzbarsky-apple]

Workflow issues

The QEMU ESP32 tests start and stop the platform manager several times, and the
lack of a shutdown implementation is putting things in a bad state.

And the test runner is not catching this bad state, so we are passing even though we crashed quite early in the test run and most of the tests did not run.

Platform

esp32, freeRTOS

Anything else?

No response