Add apt2.sebeka.k12.mn.us repo

Ubuntu 24.04 and older

curl https://apt2.sebeka.k12.mn.us/apt2.sebeka.k12.mn.us.pub | sudo tee /etc/apt/trusted.gpg.d/apt2.sebeka.k12.mn.us.pub
echo "deb [arch=amd64 signed-by=/etc/apt/trusted.gpg.d/apt2.sebeka.k12.mn.us.pub] https://apt2.sebeka.k12.mn.us/ stable main" | sudo tee /etc/apt/sources.list.d/apt2.sebeka.k12.mn.us.list
apt update

Ubuntu 26.04 and newer

curl -fsSL https://apt2.sebeka.k12.mn.us/apt2.sebeka.k12.mn.us.pub | gpg --dearmor | sudo tee /etc/apt/keyrings/apt2.sebeka.k12.mn.us.gpg > /dev/null
echo "deb [arch=amd64 signed-by=/etc/apt/keyrings/apt2.sebeka.k12.mn.us.gpg] https://apt2.sebeka.k12.mn.us/ stable main" | sudo tee /etc/apt/sources.list.d/apt2.sebeka.k12.mn.us.list
apt update