Enable disable_dev_mode feature in risc0 before mainnet

[ercecan]

In #1653 In order to implement an e2e test for unverifiable batch proofs in light client circuit we had to use fake receipts and, for fake receipts to be verified we had to activate sys-getenv feature of risc0-zkvm-platform in light client guest.sys-getenv reads env vars from host (in our case it reads RISC0_DEV_MODE to verify fake receipts). In mainnet, to avoid complications with verification, we must enable disable_dev_mode feature.