Update MILESTONES within sig-release repo => align to timing master

[RolaH1t]

Dear All,
as PI planning is currently underway, I pledge to immediately update the available milestones as follows:
milestone 23.12 => keep naming and due date of 08-Dec-2023.
milestone 24.03 => keep naming but update due date to 08-Mar-2024.
milestone 24.06 => update naming to 24.05 and update due date to 24-May-2024.
All of that will the be in complete alignment to the timing masterplan of Consortia & Association.
Comments welcome,
Roland

[FaGru3n]

updated on https://github.com/eclipse-tractusx/sig-release/milestones

[RolaH1t]

Perfect - thank You so much.
Discussion completed.