fix(ci): correct issue where docker image on PR couldn't be scanned b…

[jacdavi]

🗣 Description

This corrects an issue where the pipeline would fail on external PRs because the docker image was not published and therefore couldn't be scanned.
Now the image is stored locally on PRs so the scan could complete.

💭 Motivation and context

Fixes failing pipelines on PRs.

🧪 Testing

This PR is a test itself

✅ Pre-approval checklist

• This PR has an informative and human-readable title.
• PR targets the correct parent branch (e.g., main or release-name) for merge.
• Changes are limited to a single goal - eschew scope creep!
• Changes are sized such that they do not touch excessive number of files.
• All future TODOs are captured in issues, which are referenced in code comments.
• Related issues these changes resolve are linked preferably via closing keywords.
• All relevant repo and/or project documentation updated to reflect these changes.
• All automated checks (e.g., linting, static analysis, unit/smoke tests) passed.

✅ Post-merge checklist

• Feature branch deleted after merge to clean up repository.
• Verified that all checks pass on parent branch (e.g., main or release-name) after merge.