Bump to core 6.7.0 and olf 1.15.0

[olperr1]

⚠️ To do before merging:

• CI changes must be reverted;
• SNAPSHOT versions should be removed from pom.xml.

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?

No

What kind of change does this PR introduce?

Dependency update + adaptations

Does this PR introduce a new Powsybl Action implying to be implemented in simulators or pypowsybl?

• Yes
• No

What is the current behavior?

Uses powsybl-core 6.6.0 and powsybl-open-loadflow 1.14.0

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

Uses powsybl-core 6.7.0 and powsybl-open-loadflow 1.15.0

• Contains:
  • Fix unit tests (adapt to core-3272) (Fix unit tests (adapt to core-3272) #179)

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:

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

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

See analysis details on SonarQube Cloud