subnet owner can update ck burn

[open-junius]

Description

Related Issue(s)

• Closes #[issue number]

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• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
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[github-actions]

@opentensor/cerebrum / @opentensor/gyrus / @opentensor/cortex breaking change detected! Please prepare accordingly!

[bdmason]

This is an abandonment of the plan from last week's Open Dev call where burn started at 1% for 30 days, then increased 1% per day for 17 days up to 18%.

[Swamination-Yuma]

I believe this is this already integrated in #1996?
Also, the decision to allow subnets to control what childkeying does has a great impact on validators. Validators already set their own delegate take rate and child key take rate; why allow subnets to determine what childkeyers generate on the backs of those performing the validation work? The relationship is validator-to-validator. Subnets are highly likely to set this burn to zero, making the feature largely worthless when under subnet control.