Flaky test in position_notebook.ipynb

[Bintousk]

Describe the bug
Hello,
I noticed an error during the Tech lab event.
The test test_positionUpdateShortBlock in position_notebook.ipynb is not consistent with the expected behaviour.
It is expecting an exception when the input value for implementations.positionSolution.position.addPosition is negative.
This behaviour is not conform with the problem requierements and is contradicting an other test (test_positionUpdates ) that is expected a successfull result when using a negative value as input for implementations.positionSolution.position.addPosition.

To Reproduce
Steps to reproduce the behavior:

1. Go to 'bbit-learning-labs/PortfolioManager/1-Positions/position_notebook.ipynb.'
2. Implement solution.
3. Run test cell few times.
   4.Error will show up after few executions because it has a dependancy with a random value.

Expected behavior
The test test_positionUpdateShortBlock in position_notebook.ipynb should be removed as negative values are supported by implementations.positionSolution.position.addPosition.

Screenshots
Bellow are the screenshots of the test being flaky.
test_positionUpdates is failling if a negative input is randomly generated.

Environment (please complete the following information):

• Operating System and Version: macOS 15.3 (24D60)