Bump actions/upload-artifact from 3 to 4

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 3 to 4.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v3...v4)

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

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

.github/workflows/apt-update.yml

@@ -21,7 +21,7 @@ jobs:
     - name: update apt.json
       run: .github/scripts/apt_update.sh --file .docker/apt.json
 
-    - uses: actions/upload-artifact@v3
+    - uses: actions/upload-artifact@v4
       with:
         name: apt.json
         path: .docker/apt.json

.github/workflows/test.yml

@@ -227,7 +227,7 @@ jobs:
         run: grep '${{ github.event.repository.html_url }}' ${{ github.workspace }}/tests/full/_site/index.html
 
       - name: Upload build output artifacts
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         if: always()
         with:
           name: verify-output-verify-html
@@ -254,7 +254,7 @@ jobs:
         run: grep 'https://swedbankpay.github.io/jekyll-plantuml-docker/' ${{ github.workspace }}/tests/full/_site/index.html
 
       - name: Upload build output artifacts
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         if: always()
         with:
           name: verify-output-build-html