deps(actions): bump actions/upload-artifact from 4 to 6 (#16)

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 4 to 6.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](https://github.com/actions/upload-artifact/compare/v4...v6)

---
updated-dependencies:
- dependency-name: actions/upload-artifact
  dependency-version: '6'
  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>

.github/workflows/ci.yml

@@ -178,7 +178,7 @@ jobs:
 
       - name: Upload coverage report
         if: always()
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: test-coverage
           path: coverage/
@@ -230,7 +230,7 @@ jobs:
           echo "Build successful - BUILD_ID: $(cat .next/BUILD_ID)"
 
       - name: Upload build artifacts
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: build-output
           path: |
@@ -325,7 +325,7 @@ jobs:
 
       - name: Upload Playwright report
         if: always()
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: playwright-report
           path: playwright-report/

.github/workflows/security.yml

@@ -141,7 +141,7 @@ jobs:
 
       - name: Upload test results
         if: always()
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: security-test-results
           path: |