### Proposed changes

This PR revives #1474 by rebasing and modifying to fit the latest
changes to pulumi-eks and ci-mgmt.

Changes made:

- Restructure the go modules to align with bridged providers for now
- Generated ci-mgmt workflows
- Added kubectl installation as a setup step
- Runs all tests in parallel across 25 shards (including upgrade tests)

Passing alpha release:
https://github.com/pulumi/pulumi-eks/actions/runs/13015734092

### Related issues (optional)

<!--Refer to related PRs or issues: #1234, or 'Fixes #1234' or 'Closes
#1234'.
Or link to full URLs to issues or pull requests in other GitHub
repositories. -->