fix: use --system flag for uv pip install in workflow

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Co-Authored-By: Claude <noreply@anthropic.com>

Author: PedramNavid

.github/workflows/notebook-diff-comment.yml

@@ -27,7 +27,7 @@ jobs:
         run: uv python install 3.11
 
       - name: Install nbdime
-        run: uv pip install nbdime
+        run: uv pip install --system nbdime
 
       - name: Get changed notebooks
         id: changed-notebooks