generation to retraction_alert function

  - PR of hop client that adds avro support (note this breaks hash verification
    in poetry)
  - voeventparse

kafka boolean and adding logic to use bootstep when a worker uses the kafka
queue

- Fix failing detchar test for python3.9
- Restrict ligo.em-bright < 1.0 until SCCB approval. See !854
Using importlib resources on a data path leads to IsADirectory
error. Replaced with pathlib.

Reason for manual update of hash: https://github.com/python-poetry/poetry/issues/4523

- bump p-astro to a pre-release v1.0.0dev1, stripping all em-bright components
- add ligo.em-bright dependency