CI is failing creating html from notebooks

[woodsp-ibm]

Nightly CI has been failing for the past 3 days (the contents of the repo have not changed at all in that time).

/home/runner/work/qiskit-algorithms/qiskit-algorithms/docs/tutorials/02_vqe_advanced_options.ipynb:161: ERROR: Unexpected indentation.
/home/runner/work/qiskit-algorithms/qiskit-algorithms/docs/tutorials/02_vqe_advanced_options.ipynb:169: ERROR: Unexpected indentation.
/home/runner/work/qiskit-algorithms/qiskit-algorithms/docs/tutorials/02_vqe_advanced_options.ipynb:172: ERROR: Content block expected for the "raw" directive; none found.
/home/runner/work/qiskit-algorithms/qiskit-algorithms/docs/tutorials/02_vqe_advanced_options.ipynb:191: ERROR: Unexpected indentation.
/home/runner/work/qiskit-algorithms/qiskit-algorithms/docs/tutorials/02_vqe_advanced_options.ipynb:199: ERROR: Unexpected indentation.
/home/runner/work/qiskit-algorithms/qiskit-algorithms/docs/tutorials/02_vqe_advanced_options.ipynb:202: ERROR: Content block expected for the "raw" directive; none found.

One change that I do notice is that nbconvert is now 7.14.0, and has been failing since that version, where the last time it passed was when 7.13.1 was the latest. It appears to be similar to this issue raised on nbconvert jupyter/nbconvert#2092

[woodsp-ibm]

I'll leave this open so the pinning, done by #119, can be addressed as needed in the future