Adjust dry run for release workflow

[pdabelf5]

Proposed changes

• Don't run Trivy scans on dry run
• Avoid submitting preflight results for certification on dry run

Checklist

Before creating a PR, run through this checklist and mark each as complete.

• I have read the CONTRIBUTING doc
• I have added tests that prove my fix is effective or that my feature works
• I have checked that all unit tests pass after adding my changes
• I have updated necessary documentation
• I have rebased my branch onto main
• I will ensure my PR is targeting the main branch and pulling from my branch from my own fork

[Copilot]

Pull Request Overview

This PR adjusts the release workflow to properly handle dry run mode by skipping security scans and certification submissions that shouldn't occur during testing.

• Skip Trivy security scans entirely during dry run mode
• Conditionally add the --submit flag to preflight checks only when not in dry run mode

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