Upgrade PsySH to v0.11.15 to get PHP 8.2 compatibility

Summary:
An initial upgrade was proposed to PsySH v0.11.13, but has the following
issue under PHP 8.2: Undefined constant "Psy\Readline\Hoa\DS".
Reported upstream under https://github.com/bobthecow/psysh/issues/757

The 0.11.15 version includes this fix, so we can remove the hotfix
from WindRiver and install it through Salt.

Changes: https://github.com/bobthecow/psysh/compare/v0.11.11...v0.11.15

Test Plan: Remove hotfix for psysh on WindRiver, deploy, run psysh.

Reviewers: dereckson

Reviewed By: dereckson

Differential Revision: https://devcentral.nasqueron.org/D3009