SIMD-0685: Loader V3: Remove ExtendProgram

SIMD-0685 (Loader V3: Remove ExtendProgram) is a Core Standard Solana Improvement Document by Joe Caulfield (Anza), Alexander Meißner (Anza), Dean Little (Blueshift); proposal status Review.

Its feature gate is not active on mainnet-beta, testnet and devnet yet.

Feature gates

Vortex Testnet