build(deps): bump actions/upload-artifact from 5 to 6 (#1239)

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 5 to 6.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](https://github.com/actions/upload-artifact/compare/v5...v6)

---
updated-dependencies:
- dependency-name: actions/upload-artifact
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/rust.yml

@@ -72,7 +72,7 @@ jobs:
           if [ "${{ runner.os }}" == "Windows" ]; then EXT=".exe"; fi
           cp "target/release/pumpkin$EXT" "dist/pumpkin-${{ runner.arch }}-${{ runner.os }}$EXT"
       - name: Export executable
-        uses: actions/upload-artifact@v5
+        uses: actions/upload-artifact@v6
         with:
           name: pumpkin-${{ runner.arch }}-${{ runner.os }}
           compression-level: 9