deprecate unused legacy vote tx plumbing

Active on mainnet-beta (epoch 656), testnet (epoch 671) and devnet (epoch 730).

Minimum versions: Agave v1.18.7.

Introduced in anza-xyz/agave PR #274.

Feature id 6Uf8S75PVh91MYgPQSHnjRAPQq6an5BDv9vomrCwDqLe.

Related

• SIMD-0138

Vortex

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