update for staking precompile doc

[open-junius]

Please follow below guidelines while creating the issue.

1. Is this a bug, or an enhancement, or a suggestion for a new doc section?
   Now, there is a new staking precompile implementation in subtensor. need to update the doc in https://docs.bittensor.com/evm-tutorials/staking-precompile
2. Describe the issue in detail. More details will help address the issue better.
   use the stking precompile v2 in documentation. it is recommended, V1 is deprecated.
3. Add links to the doc pages for which you are submitting this Issue.
   test case for reference: https://github.com/opentensor/subtensor/blob/devnet-ready/evm-tests/test/staking.precompile.add-remove.test.ts
   abi file: https://github.com/opentensor/subtensor/blob/devnet-ready/precompiles/src/solidity/stakingV2.abi
   solidity code: https://github.com/opentensor/subtensor/blob/devnet-ready/precompiles/src/solidity/stakingV2.sol