OPTIC not available for arm64

Using Docker on a Mac M1 (arm64), I try to run OPTIC:
```sh
(planutils) root@8f6fe7a98cf4:~$ optic

Package not installed!
Download & install? [Y/n] y
optic will be installed.

About to install the following packages: optic (297MB)
Proceed? [Y/n]
Installing optic...
INFO: Downloading network image
296.5MiB / 296.5MiB [=================================================================================================================================================================================================================] 100 % 24.6 MiB/s 0s
Finished installing optic (size: 297M)
Successfully installed optic!

Original command: optic
Re-run command? [Y/n]
FATAL: could not open image /root/.planutils/packages/optic/optic.sif: the image's architecture (amd64) could not run on the host's (arm64)
```
It fails because the binary package downloaded by planutils is for amd64.