`isl.QPolynomial` and `isl.PwQPolynomial` var names inaccessible

[a-alveyblanc]

Describe the bug
isl.QPolynomial.get_var_names / isl.PwQPolynomial.get_var_names internally calls get_dim_name which does not exist for QPolynomial / isl.PwQPolynomial, resulting in an error.

To Reproduce

import islpy as isl


pw_qpoly = isl.PwQPolynomial("[n] -> { [i] -> 2 * i + n }")
pw_qpoly.get_var_names(isl.dim_type.param)

# alternatively
# qpoly = pw_qpoly.get_pieces()[0][1]
# qpoly.get_var_names(isl.dim_type.param)

Expected behavior
Return names of vars.

Environment (please complete the following information):

• OS: Linux
• Python version: 3.13

[inducer]

#203 should patch this. Do you want a release with that?

[a-alveyblanc]

Yes, a release with that would be great. Thanks!

[inducer]

https://github.com/inducer/islpy/releases/tag/v2026.1

Should appear on the package index once this completes: https://github.com/inducer/islpy/actions/runs/21415711196