python3.12 support

[sirtoobii]

Use importlib.resources instead of the deprecated pkg_resources.

The load_dsdl() step fails on Python3.12 since pkg_resources is being depreciated. This PR implements using the newer importlib.resources.files method to get the dsdl_path while still allowing to fallback to the older pkg_resources approach.

Error message when running the "dump all" example (without this PR, Ubuntu 22.04)

DSDL load exception: No module named 'pkg_resources'
Traceback (most recent call last):
  File "/home/tobias/Documents/sw-rid-beacon/main.py", line 6, in <module>
    import dronecan, time, math
  File "/home/tobias/Documents/sw-rid-beacon/venv/lib/python3.12/site-packages/dronecan/__init__.py", line 226, in <module>
    import dronecan.app as app
  File "/home/tobias/Documents/sw-rid-beacon/venv/lib/python3.12/site-packages/dronecan/app/__init__.py", line 12, in <module>
    from . import dynamic_node_id
  File "/home/tobias/Documents/sw-rid-beacon/venv/lib/python3.12/site-packages/dronecan/app/dynamic_node_id.py", line 25, in <module>
    class CentralizedServer(object):
  File "/home/tobias/Documents/sw-rid-beacon/venv/lib/python3.12/site-packages/dronecan/app/dynamic_node_id.py", line 26, in CentralizedServer
    QUERY_TIMEOUT = uavcan.protocol.dynamic_node_id.Allocation().FOLLOWUP_TIMEOUT_MS / 1000  # @UndefinedVariable
                    ^^^^^^^^^^^^^^^
AttributeError: 'Namespace' object has no attribute 'protocol'

[davidbuzz]

does this still work in older python/s?

[sirtoobii]

Yes, I was however only able to test it with 3.9 as I have currently no easy access to older versions