- Replaced OpenIndiana VM with OmniOS VM in Illumos build steps across `rust.yml` and `release.yml` workflows.
- Updated related workflow labels and comments for consistency.
- Deleted the Jenkinsfile, transitioning all CI workflows to GitHub Actions.
- Added Illumos (OpenIndiana) build and release steps to GitHub workflows.
- Created a new release pipeline triggered by version tags starting with `v`.
- Updated README with release instructions using `cargo-release`.
- Renamed `pkg6dev` to `pkg6` across build scripts, workflows, and documentation.
- Added support for additional binaries (`pkg6repo` and `pkg6depotd`) in release builds.
- Disabled `RUSTFLAGS` warnings-as-errors policy in workflows for improved flexibility.
- Simplified error handling in `manifest_fmri` with streamlined conditionals.
- Introduced `#[allow(clippy::result_large_err)]` to suppress clippy warnings for large error types.
