New Features
- Add option to specify sampler used in `MockDWaveSampler` (new default is now `SteepestDescentSampler`). See https://github.com/dwavesystems/dwave-system/pull/537.
- Add support for Python 3.13. See https://github.com/dwavesystems/dwave-system/pull/541.
- Add `LinearAncillaComposite`. See https://github.com/dwavesystems/dwave-system/pull/530.
Fixes
- Fix inconsistent sampleset interface across hybrid samplers - we make sure every `SampleSet` returned now has a working `wait_id()` method. See https://github.com/dwavesystems/dwave-system/pull/544.
Upgrade Notes
- Drop support for Python 3.8. See https://github.com/dwavesystems/dwave-system/pull/541.
- Soft-remove `VirtualGraphComposite` and its dependencies. Namely, `VirtualGraphComposite` is now just an identity wrapper around `FixedEmbeddingComposite`, `dwave-drivers` is not used anymore, and `dwave.system.cache.*` is completely removed. See https://github.com/dwavesystems/dwave-system/pull/543.