storcon_cli: remove old tenant-scatter command

[jcsp]

Problem

This command was used in the very early days of sharding, before the storage controller had anti-affinity + scheduling optimization to spread out shards.

Summary of changes

• Remove storcon_cli tenant-scatter

Checklist before requesting a review

• I have performed a self-review of my code.
• If it is a core feature, I have added thorough tests.
• Do we need to implement analytics? if so did you add the relevant metrics to the dashboard?
• If this PR requires public announcement, mark it with /release-notes label and add several sentences in this section.

Checklist before merging

• Do not forget to reformat commit message to not include the above checklist

[github-actions]

3228 tests run: 3111 passed, 0 failed, 117 skipped (full report)

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Code coverage* (full report)

• functions: 32.3% (6840 of 21155 functions)
• lines: 49.8% (53334 of 107056 lines)

* collected from Rust tests only

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_{The comment gets automatically updated with the latest test results
5120eb4 at 2024-06-21T10:44:30.264Z :recycle:}