ci: bump actions/upload-artifact SHA to current v4

Author: hyperpolymath

.github/workflows/learning-loop.yml

@@ -35,7 +35,7 @@ jobs:
 
       - name: Upload rule proposals
         if: always()
-        uses: actions/upload-artifact@65c79d7f54e76e4e3c7a8f34db0f4ac8b515c478 # v4
+        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
         with:
           name: rule-proposals
           path: shared-context/learning/rule-proposals/*.lgt
@@ -73,4 +73,4 @@ jobs:
 
     steps:
       - name: Placeholder for rule deployment
-        run: echo "Rule deployment will be implemented after approval workflow"
+        run: echo "Rule deployment will be implemented after approval workflow"