Add runs-on to the publish_chart job

[pavannd1]

Change Overview

Missed adding runs-on when fixing the bug in #3187

[Invalid workflow file: .github/workflows/release.yaml#L115](https://github.com/kanisterio/kanister/actions/runs/11411652685/workflow)
The workflow is not valid. .github/workflows/release.yaml (Line: 115, Col: 5): Required property is missing: runs-on

Pull request type

Please check the type of change your PR introduces:

• 🚧 Work in Progress
• 🌈 Refactoring (no functional changes, no api changes)
• 🐹 Trivial/Minor
• 🐛 Bugfix
• 🌻 Feature
• 🗺️ Documentation
• 🤖 Test
• 🏗️ Build

Issues

• fixes #issue-number

Test Plan

The workflow got triggered when releasing a new version and failed. Once we merge this, I will re-trigger the failed workflow.
Not testing this separately on a branch due to time constraints.

• 💪 Manual
• ⚡ Unit test
• 💚 E2E