fix: bump upload-pages-artifact to v5 (pins internal upload-artifact)

v3.0.1 used unpinned actions/upload-artifact@v4 internally, failing
the org-wide SHA pinning requirement.

Author: bryantbiggs

.github/workflows/docs.yml

@@ -48,7 +48,7 @@ jobs:
           curl -sSfL https://github.com/lycheeverse/lychee/releases/latest/download/lychee-x86_64-unknown-linux-gnu.tar.gz | tar xz -C /usr/local/bin
           lychee --base docs/dist --no-progress docs/dist
 
-      - uses: actions/upload-pages-artifact@56afc609e74202658d3ffba0e8f6dda462b719fa # v3.0.1
+      - uses: actions/upload-pages-artifact@fc324d3547104276b827a68afc52ff2a11cc49c9 # v5.0.0
         if: github.event_name == 'push'
         with:
           path: docs/dist