Add Joris Mancini to committers for ws libs

[TheMaskedTurtle]

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)

What kind of change does this PR introduce?

Add TheMaskedTurtle (Joris Mancini) as a maintainer on the following repositories:

• powsybl-ws-commons
• powsybl-ws-dependencies

[TheMaskedTurtle]

I am Joris Mancini working in RTE in the the Gridsuite project.I am a Tech Lead in the Gridsuite Team

We work closely with the powsybl project and make extensive use of their libraries. We actively contribute to powsybl development and participate in various meetings to clarify requirements.

Regarding webs service libs, we are for now the only users and contributors for these repositories. Developments are thought and planned in our teams, so it would greatly improve our velocity if I could have the rights to make devs reach their hands directly.