Bump actions/checkout from v6 to v7 in /.github/workflows

[UltralyticsAssistant]

Bump actions/checkout 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

🔄 This PR updates several GitHub Actions workflows in ultralytics/docs to use actions/checkout@v7 instead of @v6, keeping the docs repository’s automation current.

📊 Key Changes

• Upgraded actions/checkout from v6 to v7 in four workflow files:
  • .github/workflows/links.yml
  • .github/workflows/links_local.yml
  • .github/workflows/sitemaps.yml
  • .github/workflows/tag.yml
• Applied the update across multiple automation tasks, including:
  • 🌐 link checking
  • 🧪 local link validation
  • 🗺️ sitemap generation
  • 🏷️ tagging-related workflows
• No workflow logic or behavior was otherwise changed; this is a version refresh only.

🎯 Purpose & Impact

• Improves ⚙️ maintenance by keeping GitHub Actions dependencies up to date.
• Helps support 🔒 security, compatibility, and reliability in CI/CD workflows.
• Reduces the chance of future issues caused by using older action versions.
• For users and contributors, the impact should be minimal and mostly behind the scenes ✅, but it helps keep docs automation stable and healthy.