Bump actions/download-artifact from 7 to 8

Bumps [actions/download-artifact](https://github.com/actions/download-artifact) from 7 to 8.
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](https://github.com/actions/download-artifact/compare/v7...v8)

---
updated-dependencies:
- dependency-name: actions/download-artifact
  dependency-version: '8'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

.github/workflows/build_all.yml

@@ -109,7 +109,7 @@ jobs:
       - name: Apt-Install Dependencies
         uses: ./.github/actions/apt-install-deps
       - name: Restore Test Artifact
-        uses: actions/download-artifact@v7
+        uses: actions/download-artifact@v8
         with:
           name: ${{ github.sha }}-tests
       - uses: lukka/get-cmake@latest

.github/workflows/build_orca.yml

@@ -128,14 +128,14 @@ jobs:
 
       - name: Download macOS arm64 app bundle
         if: contains(inputs.os, 'macos') && inputs.macos-combine-only
-        uses: actions/download-artifact@v7
+        uses: actions/download-artifact@v8
         with:
           name: OrcaSlicer_Mac_bundle_arm64_${{ github.sha }}
           path: ${{ github.workspace }}/mac_bundles/arm64
 
       - name: Download macOS x86_64 app bundle
         if: contains(inputs.os, 'macos') && inputs.macos-combine-only
-        uses: actions/download-artifact@v7
+        uses: actions/download-artifact@v8
         with:
           name: OrcaSlicer_Mac_bundle_x86_64_${{ github.sha }}
           path: ${{ github.workspace }}/mac_bundles/x86_64