Bump actions/upload-artifact from 3 to 4

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 3 to 4.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v3...v4)

---
updated-dependencies:
- dependency-name: actions/upload-artifact
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/ci.yml

@@ -58,7 +58,7 @@ jobs:
         ls -Name "*.*" | foreach {
           tar acf "../artifact/${_}.tar.xz" $_
         }
-    - uses: actions/upload-artifact@v3
+    - uses: actions/upload-artifact@v4
       with:
         name: statichtml-${{ matrix.os }}-${{ matrix.ruby }}
         path: /tmp/artifact/*.*.tar.xz
@@ -84,7 +84,7 @@ jobs:
         git diff --no-index html.base html.pr --stat || true
         git diff --no-index html.base html.pr --output artifact/html.diff || true
       if: ${{ steps.generate_base.outcome == 'success' }}
-    - uses: actions/upload-artifact@v3
+    - uses: actions/upload-artifact@v4
       with:
         name: diff-${{ matrix.os }}-${{ matrix.ruby }}
         path: /tmp/artifact/html.diff