`boot-disk` parameter does not seem to be optional when updating an instance

[paudmir]

According to CLI docs:
"--boot-disk
The disk the instance is configured to boot from. Setting a boot disk is optional but recommended to ensure predictable boot behavior. The boot disk can be set during instance creation or later if the instance is stopped"

However, if we don't define it in our command, we get a failure:

oxide --insecure --timeout 300 --profile oxide24 instance update  --instance fio-instance-mlsc  --ncpu
s 4  --memory 16GiB --project verdant-df --auto-restart-policy never --cpu-platform amd_turin
error: the following required arguments were not provided:
  --boot-disk <boot-disk>

[david-crespo]

This error is coming from the CLI. In the OpenAPI schema, boot_disk is required to be present but nullable. The CLI could turn the absence of --boot-disk into boot_disk: null

[david-crespo]

I think this is the same issue: #1279