DC security analysis: RHS is not invalidated

[annetill]

Please check if the PR fulfills these requirements

• The commit message follows our guidelines
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

Does this PR already have an issue describing the problem?

Yes, powsybl/pypowsybl#758

What kind of change does this PR introduce?

Nothing for the moment, just a unit test that shows the bug. In DC security analysis only, equations can have rhs. If the rhs of these equations changed, because in contingency for example, but it could be a tap position change of a P0 change for HVDC, we have to invalidate the DC target vector. It is not the case on main branch.

We have the issue just today because it was hidden before through the sensitivity analysis API.

What is the current behavior?

What is the new behavior (if this is a feature change)?

Does this PR introduce a breaking change or deprecate an API?

• Yes
• No

If yes, please check if the following requirements are fulfilled

• The Breaking Change or Deprecated label has been added
• The migration steps are described in the following section

What changes might users need to make in their application due to this PR? (migration steps)

Other information:

[vidaldid-rte]

Looks good to me.
Maybe you could add a similar test for AC (although it should logically not be subject to this bug)

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud