Xtrack

**Changes:**
- Introduce `ParticlesInjectionSample` element.
- Fix issue with line save/reload when `energy_program` is set.
- Disable notebook progress indicator due to issue in underlying library (fall back on terminal).
- Reset `_t_last_update_time_dependent_vars` if tracking is restarted.
- Fix issue with progress `time_last_track` when progress bar is active.

**Full Changelog**: https://github.com/xsuite/xtrack/compare/v0.46.3...v0.46.4

**Changes:**
- Fix in tapering (correct behavior in case probe particle is lost in preliminary check).
- Fix in LineSegmentMap for frozen longitudinal motion.
- Small ring example

**Full Changelog**: https://github.com/xsuite/xtrack/compare/v0.46.2...v0.46.3

**Changes:**
- Introduce method for fast insertion of several thin elements.
- Add `_end_point` to output of `line.get_table()`.
- Add info from `Line.attr` in the output of `line.get_table(attr=True)`.
- Better error message on particles lost in twiss.
- Improvement in docstrings.
- Example changing HL-LHC beta*.
- Example matching "on_disp" knobs.

**Full Changelog**: https://github.com/xsuite/xtrack/compare/v0.46.1...v0.46.2

**Changes:**
- Fix in tests for GPU

**Full Changelog**: https://github.com/xsuite/xtrack/compare/v0.46.0...v0.46.1

**Changes:**
- Updat interface for inequalities in `Optimizer`. Add support for smooth transition at inequality boundary.
- Introduce `Target.freeze()` and `Target.unfreeze()`.
- Fix issue with empty `MultiSetter`.
- Use progress bars instead of counters.
- Remove need for tracker in `Line.survey`.
- In tests assert that no buffers are allocated at the end of each test (avoid memory leakage).

**Full Changelog**: https://github.com/xsuite/xtrack/compare/v0.45.0...v0.46.0

**Changes:**
- Add chromatic functions (ax, ay, bx, by, wx, wy) to twiss results.
- Reduce memory consumption in `test_radiation`
- Add properties to `TwissInit` to obtain the corresponding lattice functions.

**Full Changelog**: https://github.com/xsuite/xtrack/compare/v0.44.1...v0.45.0