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/main.yml

@@ -51,7 +51,7 @@ jobs:
         run: |
           bin/rails test:system --trace HEADLESS=true CUPRITE=true CUPRITE_JS_ERRORS=true APP_HOST='127.0.0.1'
       - name: Upload failed system test images
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         if: steps.system-test.outcome=='failure'  ||  steps.system-test-retry-1.outcome=='failure' # check the step outcome, retry 1st time
         with:
           path: ./tmp/capybara/screenshots/failures_*.png