Bug in `rng_fn` of `HalfStudentT`

[ricardoV94]

pymc/pymc/distributions/continuous.py

Line 2483 in b7764dd

return np.asarray(np.abs(stats.t.rvs(nu, sigma, size=size, random_state=rng)))

sigma should be passed by keyword as scale, otherwise it’s read as loc

Found in https://discourse.pymc.io/t/pm-halfstudentt-dist-failing-to-give-correct-shape/11821

[Dhruvanshu-Joshi]

Hey @ricardoV94 . I am working on this and will link a PR concerning this soon.

[ricardoV94]

Closed via #6658