ci: bump actions/upload-artifact SHA to current v4 (#23)

Fixes estate-wide Hypatia Security Scan + Static Analysis Gate red. The
pinned SHA `65c79d7...` for `actions/upload-artifact@v4` no longer
resolves; current v4 = `ea165f8d`. Tracked in
`hyperpolymath/hypatia#213`.

Author: hyperpolymath

.github/workflows/ci.yml

@@ -99,7 +99,7 @@ jobs:
         continue-on-error: true
 
       - name: Upload build artifacts
-        uses: actions/upload-artifact@65c79d7f54e76e4e3c7a8f34db0f4ac8b515c478 # v4.6.0
+        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.0
         with:
           name: build-artifacts
           path: |
@@ -243,4 +243,4 @@ jobs:
           echo "Security: ${{ needs.security.result }}"
           echo "Docker: ${{ needs.docker.result }}"
           echo "Accessibility: ${{ needs.a11y.result }}"
-          echo "Deno Tests: ${{ needs.deno-test.result }}"
+          echo "Deno Tests: ${{ needs.deno-test.result }}"