Bump slackapi/slack-github-action from v3.0.2 to v3.0.3 in /.github/workflows

[UltralyticsAssistant]

Bump slackapi/slack-github-action from v3.0.2 to v3.0.3 in /.github/workflows

This PR updates GitHub Actions references in this repository.

Examples:

• Branch: actions/checkout@main stays on @main
• Major tag: actions/checkout@v4 updates to @v5
• Specific tag: astral-sh/setup-uv@v0.5.0 updates to @v0.9.4
• SHA pinned: actions/checkout@<sha> # v4.1.0 updates to the latest release SHA and tag comment

_{Made with ❤️ by Ultralytics Actions}

🛠️ PR Summary

_{Made with ❤️ by Ultralytics Actions}

🌟 Summary

🔧 This PR makes a small but important maintenance update by bumping the Slack GitHub Action in CI from v3.0.2 to v3.0.3.

📊 Key Changes

• ⬆️ Updated the GitHub Actions step used for CI failure notifications:
  • from slackapi/slack-github-action@v3.0.2
  • to slackapi/slack-github-action@v3.0.3
• 📣 This affects the workflow step that sends Slack alerts when scheduled or push-based CI runs fail in ultralytics/hub.
• 🛠️ No application code or product features were changed—this is a CI/workflow dependency update only.

🎯 Purpose & Impact

• ✅ Keeps the CI notification system up to date with the latest patch release of the Slack action.
• 🔒 May improve reliability, stability, or compatibility for failure alerts without changing existing workflow behavior.
• 👀 Helps the team catch CI issues quickly by ensuring Slack notifications continue to work as expected.
• 🚫 No direct impact on end users or platform functionality, but it supports smoother developer operations behind the scenes.