wake-word-voice-assistant/m5stack-atom-echo.yaml is a lie

[brettmiller]

The wake-word-voice-assistant/m5stack-atom-echo.yaml file doesn't enable micro-wake-word support like the yaml files for the other devices in the wake-work-voice-assistant/ directory. It instead just contains a package reference to github://esphome/firmware/voice-assistant/m5stack-atom-echo.yaml@main without micro-wake-word support.

After having micro-wake-word work great on an esp32-s3-box I attempted to enable on an atom-echo with the above mentioned file. The option for "Wake word engine location" didn't exist and investigation showed was really just using the original yaml in voice-assistant/m5stack-atom-echo.yaml. The "fake" addition was done in #167 and seems like it could cause others confusion as well.