Bump powsybl-core to 4.5.1 & powsybl-single-line-diagram to 2.6.0-SNAPSHOT

[flo-dup]

Please check if the PR fulfills these requirements (please use '[x]' to check the checkboxes, or submit the PR and then click the checkboxes)

• [x] 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? Lib updates

What is the current behavior? powsybl-single-line-diagram 2.5.0-SNAPSHOT and powsybl-core 4.4.0

What is the new behavior (if this is a feature change)? powsybl-single-line-diagram 2.6.0-SNAPSHOT and powsybl-core 4.5.1

Does this PR introduce a breaking change or deprecate an API? No