cmake from home:munix9:unstable project

For Ubuntu 20.04 run the following:

Keep in mind that the owner of the key may distribute updates, packages and repositories that your system will trust (more information).

echo 'deb http://download.opensuse.org/repositories/home:/munix9:/unstable/Ubuntu_20.04/ /' | sudo tee /etc/apt/sources.list.d/home:munix9:unstable.list
curl -fsSL https://download.opensuse.org/repositories/home:munix9:unstable/Ubuntu_20.04/Release.key | gpg --dearmor | sudo tee /etc/apt/trusted.gpg.d/home_munix9_unstable.gpg > /dev/null
sudo apt update
sudo apt install cmake