Freertos asserts are now configured the same way as all other asserts in IDF, i.e. by configuring COMPILER_OPTIMIZATION_ASSERTION_LEVEL.
Allows building with asserts on and still not finding any actual file paths in the final binary file. Alternative fix for https://github.com/espressif/esp-idf/issues/6306 Progress towards https://github.com/espressif/esp-idf/issues/5873
Doubles as a test app that building with assertions off doesn't produce warnings. Closes https://github.com/espressif/esp-idf/issues/6306