[chore]: use crates.io version of async-bb8-diesel crate

Currently we are using a [forked](https://github.com/jarnura/async-bb8-diesel) version of this dependency. We need to migrate to the crates.io version
<think>
PR Context:
- Title: chore: Move async-bb8-diesel crate to crates.io version
- Merged: 2025-05-15T12:05:55Z
- Files changed: 5 files
- Commits: 1 commits

Implementation approach:
## Type of Change
<!-- Put an `x` in the boxes that apply -->

- [ ] Bugfix
- [ ] New feature
- [ ] Enhancement
- [ ] Refactoring
- [x] Dependency updates
- [ ] Documentation
- [ ] CI/CD

## Description
<!-- Describe your changes in detail -->
Changed `async-bb8-diesel crate from custom [fork](https://github.com/jarnura/async-bb8-diesel) to crates.io [version](https://github.com/oxidecomputer/async-bb8-diesel)

### Additional Changes

- [ ] This PR modifies the API contract
- [
</think>

To implement this, you'll need to modify:


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