Bump actions/upload-artifact from 6 to 7

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 6 to 7.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v6...v7)

---
updated-dependencies:
- dependency-name: actions/upload-artifact
  dependency-version: '7'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/docker-image.yml

@@ -83,7 +83,7 @@ jobs:
           touch "${{ runner.temp }}/digests/${digest#sha256:}"
 
       - name: Upload digest
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v7
         with:
           name: digests-${{ env.PLATFORM_PAIR }}
           path: ${{ runner.temp }}/digests/*

.github/workflows/nf-test.yml

@@ -145,7 +145,7 @@ jobs:
 
       - name: Upload test results
         if: always()  # run even if tests fail
-        uses: actions/upload-artifact@v6
+        uses: actions/upload-artifact@v7
         with:
           name: nf-test-results-${{ matrix.filter }}-${{ matrix.profile }}-${{ matrix.NXF_VER }}-${{ matrix.shard }}
           path: |