Does it actually say that? Because in MS-speak, the partition that contains the boot files is called the system partition, and the partition with the system files is called the boot partition.
I'd shrink /dev/sda2 and/or /dev/sda3 (and move if necessary) to create space for a type 82 /dev/sda4 partition for swap. You don't need a separate /home partition, but you'll need to be careful and back up before installing a version update.
sda1 and sda3 are marked as bootable (according to cfdisk anyway) and sda1 is labeled "system reserved"