PR merge process is overly complex and non-atomic

[RobertKrawitz]

Describe the bug

This is multiple issues, but they are closely related and should be addressed in one fix:

1. Following a PR merge, the github-action bot runs e2e testing, then does a second merge to the mainline to increment the version (in .bumpversion.cfg and setup.py). This results in (at least) two merges per PR, making the history unnecessarily confusing.
2. If the e2e testing fails, the github-action does not bump the version. This requires an additional PR to be opened to manually increment the version.

The proper method would be for the pre-merge CI to run all desired tests and either merge the PR, including the incremented version, or not. The e2e CI requires building a new container image; that image should only be promoted following successful e2e testing and be combined with the PR merge.