Update VQE tutorial to have SPSA optimizer

[nathanearnestnoble]

URL to the relevant tutorial

https://github.com/Qiskit/documentation/blob/main/docs/tutorials/spin-chain-vqe.ipynb

Select all that apply

• [ ] new content request
• [ ] typo
• [ ] code bug
• [ ] out-of-date content
• [ ] broken link
• [x] other

Describe the fix or the content request.

right now spin chain vqe tutorial uses cobyla optimizer. SPSA is generally best for noise in hardware, and can be easily coded up.

For new content requests - if the request is accepted, do you want to write the content?

I only want to review the material when it's finished

[ritajitmajumdar1]

Good to see this coming through.