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

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

Author: dependabot[bot]

.github/workflows/copilot-setup-steps.yml

@@ -124,7 +124,7 @@ jobs:
           : > /home/runner/work/_temp/runtime-logs/blocked.md
 
       - name: Upload Copilot runtime logs (if present)
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: copilot-runtime-logs
           path: |

.github/workflows/e2e.yml

@@ -83,23 +83,23 @@ jobs:
 
       - name: 📊 Upload test results
         if: always()
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: playwright-report-${{ matrix.browser }}
           path: playwright-report/
           retention-days: 7
 
       - name: 📹 Upload test videos
         if: failure()
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: test-videos-${{ matrix.browser }}
           path: test-results/**/*.webm
           retention-days: 7
 
       - name: 📸 Upload test screenshots
         if: failure()
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: test-screenshots-${{ matrix.browser }}
           path: test-results/**/*.png