[FlyteCTL Feature] Remove support for storage flag

[eapolinario]

Describe the feature/command for FlyteCTL

We should drop the storage flag entirely now that past Flyte 1.0.

In https://github.com/flyteorg/flytectl/pull/296 we removed the need for users to define a storage stanza in their config files and in https://github.com/flyteorg/flytectl/pull/319 we stopped inserting that stanza in the generated config files, however the flag is still present in the latest versions of the flytectl.

Provide a possible output or UX example

We have users confused about the support of that flag in flytectl (e.g. [1]). Since we no longer support we should drop it entirely.

Are you sure this issue hasn't been raised already?

• [X] Yes

Have you read the Code of Conduct?

• [X] Yes