rtl repositories no longer available

Summary

The repositories from git.rtems.org mentioned here are no longer available:

• https://gitlab.rtems.org/rtems/tools/rtems-tools/-/blob/main/linkers/main-page.cpp?ref_type=heads#L244
• https://gitlab.rtems.org/rtems/tools/rtems-tools/-/blob/main/linkers/main-page.cpp?ref_type=heads#L256

Steps to reproduce