Rampup port: Fix genesis ledger directory growing in size

[georgeee]

Port of PR Fix genesis ledger directory growing in size #1473 that is in berkeley, but evaded rampup sadly.

Explain how you tested your changes:

• Not tested

Checklist:

• Dependency versions are unchanged
  • Notify Velocity team if dependencies must change in CI
• Modified the current draft of release notes with details on what is completed or incomplete within this project
• Document code purpose, how to use it
  • Mention expected invariants, implicit constraints
• Tests were added for the new behavior
  • Document test purpose, significance of failures
  • Test names should reflect their purpose
• All tests pass (CI will check this if you didn't)
• Serialized types are in stable-versioned modules
• Does this close issues? None

[georgeee]

!ci-build-me

[emberian]

Rubber stamping this port, but gonna make a quick follow up PR to use File_system.create_dir

[deepthiskumar]

!approved-for-mainnet