Get rid of pycoral dependency?

[iingram]

Currently, camml depends on the pycoral package which is not served on PyPI and therefore can't simply be installed with pip and via setup.py. This isn't ideal. It might be worth changing the code to do inference directly with tflite and therefore removing the dependency on the pycoral package.

[iingram]

@kgarwoodsdzwa also has discovered that the pycoral package is not even being kept current enough to work with newer versions of other elements of system (Katie, can you do a quick synopsis of that in a comment in this issue? Feels as if you're on a path to tackle these issues and ideally remove the pycoral dependency quickly but might make sense to capture at least a smidgen in case we suddenly get pulled away from this, as happens. :-) ) so there's even greater need to drop this dependency in favor of doing things directly in tflite_runtime.

[iingram]

• we're specifically now targeting the most current version of Raspberry Pi OS, bookworm, for our systems that need camml (scrubcam, an important dependent of camml, had not been updated to picamera2 so we'd been continuing to use buster because there was no bandwidth to do anything about that but there's now active synchronous work to address that so the time is now to catch up to the present)
• libedgetpu has not been kept very up-to-date and is definitely not up-to-date with the version of tflite-runtime available on bookworm.
• but very recently a contributor addressed that in his own fork of libedgetpu and published Debian packages that fix the problem here: https://github.com/feranick/libedgetpu/releases/tag/v16.0-TF2.15.0-1
• so the least kludgy path at this stage seems to be to use this *.deb (possibly include it directly with the camml repo)
• worth noting that having to install a Debian package does still mean there's no clean pip install of camml