## Summary

Add a new feature to disable rent fees collections.

## Motivation

The total number of rent paying accounts on solana network is phasing out. And
it is no longer possible to create new rent paying account on the network.
Therefore, when all the rent paying accounts are gone in the network, we would
like to disable rent fee collection on the network through a feature.


## Alternatives Considered

None

## New Terminology

None

## Detailed Design

When the feature - "disable rent fees collections" is activated, rent will no
longer be collected from accounts and distributed to validators.

The PR for this work is at https://github.com/solana-labs/solana/pull/33945

## Impact

1. Accounts, which are not "rent exempt", will no longer pay rents. And
   validators will not be paid any rent fees. (Both of these should already not
   happen when all rent paying accounts are gone.)

2. Other implementations of validator client will not need to implement rent
   processing.

3. The performance of validators will be better since there is no more rent
   processing.

## Security Considerations

Because when the feature is activated, there will be no more rent paying
accounts, and it would also be impossible to create any new rent paying accounts
on the network, there should be no security issue. However, if for some reason,
rent paying accounts still exit or are created in the network, when the feature
is activated, the network will still be alive. The only difference is just that
no more rents are collected and distributed.


## Backwards Compatibility

Incompatible.

Disable rent fees collection