Bump actions/setup-python from v6 to v7 in /.github/workflows

[UltralyticsAssistant]

Bump actions/setup-python from v6 to v7 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

Updates the documentation publishing workflow to use the latest Python setup action. ⚙️

📊 Key Changes

• Upgraded actions/setup-python from v6 to v7.
• Applied the update across all three publishing workflow jobs in .github/workflows/publish.yml.
• No changes were made to the Python version or other workflow steps.

🎯 Purpose & Impact

• Keeps the CI/CD workflow aligned with the latest GitHub Actions tooling. ✅
• Improves compatibility, maintenance, and access to updates from actions/setup-python.
• Helps ensure reliable documentation publishing without changing the existing release process. 🚀