Bump actions/download-artifact from 5 to 6

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

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

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/create_wheel.yml

@@ -103,7 +103,7 @@ jobs:
             distro: archlinux:latest
 
     steps:
-      - uses: actions/download-artifact@v5
+      - uses: actions/download-artifact@v6
         with:
           pattern: stormpy-wheels-${{ matrix.arch.name }}
           path: dist
@@ -182,7 +182,7 @@ jobs:
       - uses: maxim-lobanov/setup-xcode@v1
         with:
           xcode-version: ${{ matrix.distro.xcode }}
-      - uses: actions/download-artifact@v5
+      - uses: actions/download-artifact@v6
         with:
           pattern: stormpy-wheels-${{ matrix.distro.os }}
           path: dist

.github/workflows/release.yml

@@ -121,7 +121,7 @@ jobs:
     # Only upload if using original repo and triggered by either a release or a manual workflow dispatch
     if: ${{ github.repository_owner == 'moves-rwth' && ((github.event_name == 'release' && github.event.action == 'published') || github.event_name == 'workflow_dispatch') }}
     steps:
-      - uses: actions/download-artifact@v5
+      - uses: actions/download-artifact@v6
         with:
           # unpacks all stormpy artifacts into dist/
           pattern: stormpy-*

.github/workflows/release_docker.yml

@@ -124,7 +124,7 @@ jobs:
           - {tag: "${{ inputs.tag }}"}
     steps:
       - name: Download digests
-        uses: actions/download-artifact@v5
+        uses: actions/download-artifact@v6
         with:
           path: ${{ runner.temp }}/digests/${{ matrix.image.tag }}
           pattern: ${{ matrix.image.tag }}-digests-*