Credo upgrade causing CI to fail with exit code 8(Nesting Depth)

[YaleChen299]

Currently suppressed by setting a larger maximum depth: 5. (https://github.com/source-academy/backend/pull/957)

https://github.com/source-academy/backend/actions/runs/5369573407

Need to look into deciding the appropriate level of nesting and how to avoid that breaking in CI. Possibly need to refactor some of the functions to fit the nesting level.