point to location of `as_xtensor`

[williambdean]

Not entirely obvious where this function lives.

import pymc as pm
import pymc.dims as pmd
from pytensor.xtensor import as_xtensor


coords = {"repo": ["pymc", "pymc-marketing"]}
with pm.Model(coords=coords) as model:
    lam = pmd.HalfNormal("lam", dims="repo")
    pmd.Exponential(
        "obs",
        lam=lam,
        observed=[5, 7],
        dims="repo",
    )

ValueError: Variable [5, 7] must have dims associated with it.
To avoid subtle bugs, PyMC does not make any assumptions about the dims of parameters.
Use `as_xtensor` with the `dims` keyword argument to specify the dims explicitly.

My suggestion would be to be more explicit here with pytensor.xtensor.as_xtensor:

pymc/pymc/dims/distributions/core.py

Lines 134 to 138 in ebd836e

	raise ValueError(
	f"Variable {x} must have dims associated with it.\n"
	"To avoid subtle bugs, PyMC does not make any assumptions about the dims of parameters.\n"
	"Use `as_xtensor` with the `dims` keyword argument to specify the dims explicitly."
	)

[ricardoV94]

Doesn't it also live in pmd?