feat: update pre-mine specification (#6622)

Description
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Update pre-mine specification

Motivation and Context
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New specification.

How Has This Been Tested?
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Unit tests pass

What process can a PR reviewer use to test or verify this change?
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Breaking Changes
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- [x] None
- [ ] Requires data directory on base node to be deleted
- [ ] Requires hard fork
- [ ] Other - Please specify

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