SIG-Security GROUP by EF

[SSIRKC]

Request to EF to create a SIG Security group:
eclipse-tractusx/.eclipsefdn#46

Followed up in HelpDesk:
https://gitlab.eclipse.org/eclipsefdn/helpdesk/-/issues/4166#note_1653934

As mentioned by the system team.

[scherersebastian]

Follow up ticket: https://gitlab.eclipse.org/eclipsefdn/helpdesk/-/issues/1709

[RoKrish14]

New announcement:

1. https://github.com/orgs/eclipse-csi/discussions/4
2. https://www.eclipse.org/projects/handbook/#vulnerability-team