Stabilize pkgdown Pages deploy by upgrading GitHub Pages actions

[Copilot]

The pkgdown workflow’s deploy job was intermittently failing in GitHub Actions (Deployment failed, try again later) on the Pages deployment step. This change updates the workflow to the current GitHub Pages action versions used by the deployment pipeline.

• Workflow update: Pages artifact upload

  • Bumped .github/workflows/pkgdown.yaml from actions/upload-pages-artifact@v3 to @v4.

• Workflow update: Pages deployment

  • Bumped .github/workflows/pkgdown.yaml from actions/deploy-pages@v4 to @v5.

• Net effect

  • Aligns the pkgdown deployment path with current Pages actions/runtime expectations and removes version drift in the deploy chain.

# .github/workflows/pkgdown.yaml
- uses: actions/upload-pages-artifact@v3
+ uses: actions/upload-pages-artifact@v4

- uses: actions/deploy-pages@v4
+ uses: actions/deploy-pages@v5

[Copilot]

Pull request overview

Updates the pkgdown GitHub Actions workflow to use the current GitHub Pages action major versions, aiming to reduce intermittent Pages deployment failures by aligning with the latest Pages deployment pipeline.

Changes:

• Bump actions/upload-pages-artifact from @v3 to @v4.
• Bump actions/deploy-pages from @v4 to @v5.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.