Use np.unpackbits

[jonashaag]

Checklist

• Added a CHANGELOG.rst entry

[github-actions]

(benchmark 4461195372 / attempt 1)
Base results / Our results / Change

Model	Size	Dump Time	Load Time
sklearn rf	77.2 MiB / 11.7 MiB / 6.63 x	0.07 s / 0.11 s / 1.61 x	0.08 s / 0.11 s / 1.24 x
sklearn rf LZMA	17.3 MiB / 5.3 MiB / 3.23 x	35.89 s / 6.06 s / 0.17 x	1.67 s / 0.57 s / 0.34 x
sklearn gb	2.2 MiB / 1.1 MiB / 2.06 x	0.03 s / 0.17 s / 5.90 x	0.03 s / 0.12 s / 3.63 x
sklearn gb LZMA	0.6 MiB / 0.2 MiB / 3.82 x	0.95 s / 0.36 s / 0.38 x	0.09 s / 0.14 s / 1.57 x
LGBM gbdt	5.3 MiB / 1.9 MiB / 2.74 x	0.16 s / 0.39 s / 2.40 x	0.02 s / 0.30 s / 12.18 x
LGBM gbdt LZMA	1.7 MiB / 0.8 MiB / 1.99 x	3.10 s / 0.98 s / 0.32 x	0.16 s / 0.37 s / 2.30 x
LGBM gbdt large	5.3 MiB / 1.9 MiB / 2.74 x	0.16 s / 0.39 s / 2.38 x	0.02 s / 0.30 s / 12.10 x
LGBM gbdt large LZMA	1.7 MiB / 0.8 MiB / 1.99 x	3.09 s / 0.97 s / 0.32 x	0.16 s / 0.37 s / 2.28 x
LGBM rf	1.6 MiB / 0.5 MiB / 3.30 x	0.05 s / 0.08 s / 1.85 x	0.01 s / 0.07 s / 12.56 x
LGBM rf LZMA	0.1 MiB / 0.1 MiB / 1.70 x	0.23 s / 0.12 s / 0.54 x	0.02 s / 0.08 s / 4.04 x

[jonashaag]

RF 6.08 -> 6.63

[pavelzw]

RF LZMA
5.4 MiB / 3.18x -> 5.3 MiB / 3.23x