Integration branch and bump powsybl-core to 7.4.0-SNAPSHOT

[NathanDissoubray]

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)
• A PR or issue has been opened in all impacted repositories (if any)

Does this PR already have an issue describing the problem?

No

What kind of change does this PR introduce?

Powsybl-core version bump (including all minimal changes for CI)

What is the current behavior?

Powsybl-core version is 7.3.0

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

Powsybl-core version is 7.4.0-SNAPSHOT and including all minimal changes:

• Change IIDM file version (Change IIDM file version #1489 following Bump IIDM to 1.18 powsybl-core#3984)

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: