remove delegations from stakes cache when inactive

Active on mainnet-beta (epoch 256), testnet (epoch 237) and devnet (epoch 198).

Introduced in null PR #null.

Feature id HFpdDDNQjvcXnXKec697HDDsyk6tFoWS2o8fkxuhQZpL.

Vortex

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