Draft: Copies in nigel's test.sh fix so we can unbreak renovate/ironbank branch's gluon tests | SKIP UPDATE

General MR

Summary

!176 (merged) is blocked by what appears to be a subtle bug in the test.sh on main. If skopeo doesn't clean up after itself and remove the container image then the upgrade test can't pass.

This MR proposes to port over @nbazzeghin's two-line cleanup tweak to chart/tests/scripts/test.sh to unblock !176 (merged).

Relevant logs/screenshots

• Upgrades fail due to not having this cleanup step in force
• Clean installs pass and are able to clean up using this script

Linked Issue

Upgrade Notices

N/A