add unzip to the list of install pkgs

[crd477]

This change adds unzip to the list of pkgs installed in the chroot.

Without this change, I get the following error when during the run_chroot phase:

... =====> running build_image ... /image / --2025-04-03 00:20:00-- https://memtest.org/download/v7.00/mt86plus_7.00.binaries.zip Resolving xxx (xxx)... x.x.x.x Connecting to xxx (xxx)|x.x.x.x|:3128... connected. Proxy request sent, awaiting response... 200 OK Length: 270657 (264K) [application/zip] Saving to: 'install/memtest86.zip' 0K .......... .......... .......... .......... .......... 18% 302K 1s 50K .......... .......... .......... .......... .......... 37% 605K 0s 100K .......... .......... .......... .......... .......... 56% 31.9M 0s 150K .......... .......... .......... .......... .......... 75% 626K 0s 200K .......... .......... .......... .......... .......... 94% 23.6M 0s 250K .......... .... 100% 58.0M=0.3s 2025-04-03 00:20:01 (796 KB/s) - 'install/memtest86.zip' saved [270657/270657] /root/chroot_build.sh: line 183: unzip: command not found