CI: Add Blossom init GHA workflow

[Alexey-Rivkin]

What

Add a GitHub Action workflow to start Blossom pipeline.

Why ?

(Internal doc)
https://confluence.nvidia.com/pages/viewpage.action?spaceKey=BLOS&title=Github+Support+User+Documentation#GithubSupportUserDocumentation-Addworkflowfile

[greptile-apps]

Greptile Overview

Greptile Summary

Added GitHub Actions workflow to integrate Blossom CI pipeline, triggered by /build comments on pull requests. The workflow includes authorization checks, vulnerability scanning, and job triggering on hybrid infrastructure (GitHub + self-hosted runners).

• Workflow intentionally runs only on /build comments, not on standard PR events
• Uses internal NVIDIA Blossom templates with required actions/checkout@v2 version
• Depends on secrets BLOSSOM_KEY and CI_SERVER being configured
• The Upload-Log job runs independently on workflow_dispatch events for Jenkins log posting

Confidence Score: 4/5

• Safe to merge with minor caveat about env.args output mechanism
• The workflow follows NVIDIA's internal Blossom CI integration template and is intentionally designed for comment-triggered builds. Previously raised concerns about trigger conditions and deprecated actions were confirmed as intentional design choices by the development team. The only unresolved concern is whether the blossom-ci script properly sets env.args for job outputs, but this is likely handled by the Blossom tooling.
• No files require special attention - this is a straightforward CI integration following internal templates

Important Files Changed

File Analysis

Filename	Score	Overview
.github/workflows/blossom-ci.yml	4/5	Adds Blossom CI workflow for /build comment triggers; previously reported issues acknowledged by developers as intentional design

[greptile-apps]

_{1 file reviewed, 2 comments}

_{Edit Code Review Agent Settings | Greptile}

[greptile-apps]

_{1 file reviewed, 1 comment}

_{Edit Code Review Agent Settings | Greptile}

[greptile-apps]

_{1 file reviewed, no comments}

_{Edit Code Review Agent Settings | Greptile}