stop adding hashes for skipped slots to recent blockhashes

Active on mainnet-beta (epoch 474), testnet (epoch 465) and devnet (epoch 497).

Introduced in solana-labs/solana PR #24389.

Feature id 6iyggb5MTcsvdcugX7bEKbHV8c6jdLbpHwkncrgLMhfo.

Vortex

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