Bump the github-actions-updates group with 2 updates

Bumps the github-actions-updates group with 2 updates: [actions/upload-artifact](https://github.com/actions/upload-artifact) and [actions/download-artifact](https://github.com/actions/download-artifact).


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

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

---
updated-dependencies:
- dependency-name: actions/upload-artifact
  dependency-version: '7'
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: github-actions-updates
- dependency-name: actions/download-artifact
  dependency-version: '8'
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: github-actions-updates
...

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

Author: dependabot[bot]

.github/workflows/docker.yml

@@ -108,15 +108,15 @@ jobs:
 
       - name: upload ghcr digest
         if: github.event_name == 'push' && (github.ref == 'refs/heads/master' || startsWith(github.ref, 'refs/tags/'))
-        uses: actions/upload-artifact@v6
+        uses: actions/upload-artifact@v7
         with:
           name: digests-${{ matrix.image.name }}-ghcr-${{ matrix.platform.artifact }}
           path: /tmp/digests/${{ matrix.image.name }}/ghcr/*
           retention-days: 1
 
       - name: upload dockerhub digest
         if: github.event_name == 'push' && (github.ref == 'refs/heads/master' || startsWith(github.ref, 'refs/tags/'))
-        uses: actions/upload-artifact@v6
+        uses: actions/upload-artifact@v7
         with:
           name: digests-${{ matrix.image.name }}-dockerhub-${{ matrix.platform.artifact }}
           path: /tmp/digests/${{ matrix.image.name }}/dockerhub/*
@@ -131,14 +131,14 @@ jobs:
         image: [app, buildgo, scratch]
     steps:
       - name: download ghcr digests
-        uses: actions/download-artifact@v7
+        uses: actions/download-artifact@v8
         with:
           path: /tmp/digests/ghcr
           pattern: digests-${{ matrix.image }}-ghcr-*
           merge-multiple: true
 
       - name: download dockerhub digests
-        uses: actions/download-artifact@v7
+        uses: actions/download-artifact@v8
         with:
           path: /tmp/digests/dockerhub
           pattern: digests-${{ matrix.image }}-dockerhub-*