Merge branch '24482-support-admonition-boxes-in-markdown-rendering' into 'master'

Support Admonition Boxes in Markdown Rendering and RTE

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/178775



Merged-by: Himanshu Kapoor <hkapoor@gitlab.com>
Approved-by: Serhii Yarynovskyi Parental Leave from 2025-02-21 to 2025-06-09 <syarynovskyi@gitlab.com>
Approved-by: Buck O'Leary <bucoleary@gitlab.com>
Approved-by: Tristan Read <tread@gitlab.com>
Approved-by: Alex Fracazo <afracazo@gitlab.com>
Approved-by: Marcin Sedlak-Jakubowski <msedlakjakubowski@gitlab.com>
Reviewed-by: Brett Walker <bwalker@gitlab.com>
Reviewed-by: Tristan Read <tread@gitlab.com>
Reviewed-by: Marcin Sedlak-Jakubowski <msedlakjakubowski@gitlab.com>
Co-authored-by: Marcin Sedlak-Jakubowski <msedlakjakubowski@gitlab.com>
Co-authored-by: Brett Walker <bwalker@gitlab.com>
Co-authored-by: Chad Lavimoniere <clavimoniere@gitlab.com>