fix: array element encapsulation in ezkl_demo.ipynb

[moyedx3]

Overview

This pull request introduces a modification to the ezkl_demo.ipynb file to address a formatting issue in the array elements. The original code outputs array elements without encapsulating them in quotes, which can lead error while interacting with verifyProof contract.

Problem
Original formatted_output output lead to transaction error while interacting with verifyProof contract.

Changes made
Encapsulated each element of the formatted_output array in quotes ("").

Additional Notes

• Smart contract interaction was done by using Remix.
• The error message i got was transact to Halo2Verifier.verifyProof errored: Error encoding arguments: Error: types/values length mismatch (count={"types":2,"values":3}, value={"types":["bytes","uint256[]"], ....