use zrot

[kevinsung]

Fixes #28

Hmm apparently the performance is actually worse on my Linux machine.

| Change   | Before [b0f23065] <main>   | After [77378a2a] <pull/566/head>   |   Ratio | Benchmark (Parameter)                                                                 |
|----------|----------------------------|------------------------------------|---------|---------------------------------------------------------------------------------------|
| +        | 4.81±0.1ms                 | 8.62±0.2ms                         |    1.79 | orbital_rotation.OrbitalRotationBenchmark.time_apply_orbital_rotation_ffsim(12, 0.25) |
| +        | 119±4ms                    | 190±7ms                            |    1.59 | orbital_rotation.OrbitalRotationBenchmark.time_apply_orbital_rotation_ffsim(12, 0.5)  |
| +        | 657±5ms                    | 996±8ms                            |    1.52 | orbital_rotation.OrbitalRotationBenchmark.time_apply_orbital_rotation_ffsim(16, 0.25) |
| +        | 741±2μs                    | 966±30μs                           |    1.3  | orbital_rotation.OrbitalRotationBenchmark.time_apply_orbital_rotation_ffsim(8, 0.5)   |