Dissolutions Job - Remove/Cleanup old versioning DB artifacts

After PROD deployment of new DB versioning and if things have been looking good for a while, we want to start removing the code for the old versioning.

That also includes the removal of usage of the feature flags from the code. We will only use the code for the new versioning.

We will keep the feature flags in LD for now. We can remove later once all the cleanup is done.

This ticket takes care of the dissolutions job cleanup.

Need to handle:
- [ ] Clean the old DB artifacts from the dissolutions job
- [ ] Might need some additional misc. tweaks/removals
- [ ] Verify/test your changes and monitor if something's missing

No files or tests are named. Start by locating the dissolutions job and its old DB versioning and feature-flag references, then identify the artifacts to remove. Done means the old artifacts and their usage are cleaned up, changes are verified, and the job is monitored for missing cleanup.

Written by the indexing model from the issue text.