It might be your computer, but it’s their network - they get to set the rules as to how it gets used.

Obligatory “read your schools’ computer use policy before you get yourself in trouble for evading the firewall”

The reason openssh links liblzma in the first place is to enable a systemd feature, so naturally “systemd bad, it’s proximity to a security issue is yet more proof that a pile of shell scripts in a trenchcoat is a superior init system” etc