In this PR @gz and I had a discussion of making the dbt tests run against a pre-existing Kafka instance and updating the PyTest such that they could be env-var driven and be decoupled from Docker.

#5950

The nature of GitHub action made it so that I need to first get PRs committed before getting hands on the GH Action infra permissions.

The #5950 merges an E2E PyTest integration test, and the purpose of this task is to modularize so it works rapidly against the existing Feldera CI infra, including adding support for parallelized CI runs such that there are no noisy neighbor conflicts.