[isc-dchui]

Description

• Closes Improve CI stability by restructuring some tests #1264
• Closes CI sometimes fails on the "Stop temporary registry" step #1266
• Simplify CI steps of container cleanup into one step.
• Remove the unneeded installations of "objectscript-math" module that relied on network connection and replace with ORAS container installs.

Testing

The CI failures are intermittent so hard to directly test and proof will be in the pudding.

Checklist

• This branch has the latest changes from the main branch rebased or merged.
• Changelog entry added.
• Unit (zpm test -only) and integration tests (zpm verify -only) pass.
• Style matches the style guide in the contributing guide.
• Documentation has been/will be updated
  • Source controlled docs, e.g. README.md, should be included in this PR and Wiki changes should be made after this PR is merged (add an extra issue for this if needed)
• Pull request correctly renders in the "Preview" tab.