chore(deps): bump actions/upload-artifact from 6 to 7 (#33)

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

Author: dependabot[bot]

.github/workflows/image-build-push.yaml

@@ -135,15 +135,15 @@ jobs:
           echo "$digest" | sed 's/^sha256://' > "/tmp/digests-ghcr/${digest#sha256:}"
 
       - name: Upload digest (Docker Hub)
-        uses: actions/upload-artifact@v6
+        uses: actions/upload-artifact@v7
         with:
           name: digests-${{ matrix.version }}-${{ matrix.platform == 'linux/amd64' && 'amd64' || 'arm64' }}
           path: /tmp/digests/*
           if-no-files-found: error
           retention-days: 1
 
       - name: Upload digest (GHCR)
-        uses: actions/upload-artifact@v6
+        uses: actions/upload-artifact@v7
         with:
           name: digests-ghcr-${{ matrix.version }}-${{ matrix.platform == 'linux/amd64' && 'amd64' || 'arm64' }}
           path: /tmp/digests-ghcr/*