chore: fix PRIVATE_KEY_STORE_PATH in devnet env

Author: MarcosNicolau

examples/L2/.env.devnet

@@ -4,6 +4,6 @@ ETH_RPC_URL=http://localhost:8545
 WS_ETH_RPC_URL=ws://localhost:8546
 BEACON_CLIENT_URL=http://localhost:58801
 # Generate it with make gen_devnet_owner_wallet
-PRIVATE_KEY_STORE_PATH="contract-owner.keystore.json"
+PRIVATE_KEY_STORE_PATH="../../contract-owner.keystore.json" # This is read from crates/l2.
 PRIVATE_KEY_STORE_PASSWORD="<!w5Y%In94Vw"
 STATE_TRANSITION_CONTRACT_ADDRESS=<STATE_TRANSITION_CONTRACT_ADDRESS>