How to increase the root partition size of a virtual machine used by GNOME Boxes (QEMU)?

I use GNOME Boxes on Fedora 32 to virtualize a Fedora Silverblue installation. I did not setup a sophisticated/smart partitioning for my virtual Fedora and have run out of disk space on my virtual root partition. My objective is to be able to continue using my virtual Fedora machine as efficient and soon as possible without recreating the virtualization and without adding another partition. Therefore, how can I increase the root partition of my QEMU-based virtualization? Similar question: https://unix.stackexchange.com/questions/349586/resize-qcow2-root-parition