[IMP] sustainability: Add test for uncertainity computation

[BonnetAdam]

Self proofreading checklist

• Code Review: Have you reviewed your code to ensure it follows best practices
  and meets the project's coding standards?
• Testing: Have you tested your changes locally to ensure they work as expected?
• Documentation: Have you updated any relevant documentation or comments to
  reflect your changes?
• Pre-commit Checks: Have you ensured that pre-commit checks have automatically
  run upon committing to catch any potential issues?

[sustainabilitybot]

Hi @BonnetAdam, @jguenat, @jacopobacci,
some modules you are maintaining are being modified, check this out!

[BonnetAdam]

Maybe add more tests like this one in the future