Change `withoutError` to `withoutUncert`

[Splines]

To be consistent, use withoutUncert instead of withoutError in the results.tex.

[paul019]

Done.

[Splines]

Great 👍. You can create a PR from your branch to main. In that PR write "Resolves #38" or "Fixes #38", then it will automatically close this issue once the PR is merged.