Optimize CI Workflow: Skip Unnecessary Workflows for Draft PRs

[samzong]

Currently, many CI workflows still execute when a pull request is in draft status. This leads to unnecessary consumption of resources and delays for work that isn't ready for full review.

Proposal:

• Adjust the CI workflow configuration to skip non‑essential workflows on draft pull requests.
• Essential checks (linting, quick sanity tests) may still run, but costly integration or deployment workflows should be deferred until the PR is marked ready.

Reducing workflow execution for draft PRs will save compute time and focus attention on finalized changes.