Should fix issues with tomllib not being available in the docker related
builds, as well as the move from docker-compose to "docker compose" in
gh actions
Also adds the ability to overwrite the image in docker-compose.yml,
which allows the CI build to use the same image for all docker tests.
The default is still 'benbusby/whoogle-search' though.
Initializing the DDG bangs when running whoogle for the first time
creates an indeterminate amount of delay before the app becomes usable,
which makes usability tests (particularly w/ Docker) unreliable. This
moves the bang json init to a background thread and writes a temporary
empty dict to the bangs json file until the full bangs json can be used.
Split previous docker test CI into one for PRs and one for triggering
the main buildx workflow that deploys new images to Docker Hub.
Note that this needs to be further refactored soon to use reusable
workflows. The main portion of docker/docker-compose tests is duplicated
between the new main + test workflows.
Ben Busby