Update desired hashes per tick to 7.6M

Active on mainnet-beta (epoch 592), testnet (epoch 591) and devnet (epoch 640).

Introduced in solana-labs/solana PR #33600.

Feature id 8We4E7DPwF2WfAN8tRTtWQNhi98B99Qpuj7JoZ3Aikgg.

Vortex

• Consensus leaderboard
• Fees leaderboard
• Validators
• Stake pools
• Decentralization
• Client versions
• Cluster status
• Governance
• Feature gates
• SIMDs
• Activity
• API and AI usage