Bump actions/upload-artifact from 5 to 6 (#11797)

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/build_all.yml

@@ -106,7 +106,7 @@ jobs:
           tar -xvf build_tests.tar
           scripts/run_unit_tests.sh
       - name: Upload Test Logs
-        uses: actions/upload-artifact@v5
+        uses: actions/upload-artifact@v6
         if: ${{ failure() }}
         with:
           name: unit-test-logs
@@ -170,7 +170,7 @@ jobs:
         arch: ${{ matrix.variant.arch }}
         upload-artifact: false
     - name: Upload artifacts Flatpak
-      uses: actions/upload-artifact@v5
+      uses: actions/upload-artifact@v6
       with:
         name: OrcaSlicer-Linux-flatpak_${{ env.ver }}_${{ matrix.variant.arch }}.flatpak
         path: '/__w/OrcaSlicer/OrcaSlicer/OrcaSlicer-Linux-flatpak_${{ env.ver }}_${{ matrix.variant.arch }}.flatpak'