Trieste

**New features**
Preliminary support for categorical search spaces (863)

**Improvements/fixes**
Support Datasets with statically shaped query points and dynamically shaped observations (866)

**Full Changelog**: https://github.com/secondmind-labs/trieste/compare/v3.3.4...v3.4.0

**Improvements/fixes**
Fix assert in `filter_datasets` to not insist subspace tags is a tuple (853)
Allow `FixedLocalAcquisitionRule` with 0 local datasets (859)

**Full Changelog**: https://github.com/secondmind-labs/trieste/compare/v3.3.3...v3.3.4

**Improvements/fixes**
Fix uniqueness detection bug in dataset_len method (853)

**Full Changelog**: https://github.com/secondmind-labs/trieste/compare/v3.3.2...v3.3.3

**Improvements/fixes**
Support tf.Variables in dataset_len method (851)

**Full Changelog**: https://github.com/secondmind-labs/trieste/compare/v3.3.1...v3.3.2

**Improvements/fixes**
Support reinitialising AskTellOptimizer with extended datasets (849)

**Full Changelog**: https://github.com/secondmind-labs/trieste/compare/v3.3.0...v3.3.1

**Improvements/fixes**
Updated BatchTrustRegionRule to correctly use state, allowing it to be saved and reloaded (841)
Use correct dtype for empty Box samples (847)
Fix TREGO initialisation bug introduced in 3.1.0 (842)
Make trust region initialisation more robust (843)
Add from_state helper method to AskTellOptimizer (841)

**Full Changelog**: https://github.com/secondmind-labs/trieste/compare/v3.2.0...v3.3.0