fix: use celoutils.SafeGasLimit in place

* Gas limit is now 1M for all custodial related txs
* Precise value to be determined after testing phase is over

internal/tasker/task/account_refill_gas.go

@@ -120,7 +120,7 @@ func AccountRefillGasProcessor(cu *custodial.Custodial) func(context.Context, *a
 				InputData:       input,
 				GasFeeCap:       celoutils.SafeGasFeeCap,
 				GasTipCap:       celoutils.SafeGasTipCap,
-				GasLimit:        gasLimit,
+				GasLimit:        uint64(celoutils.SafeGasLimit),
 				Nonce:           nonce,
 			},
 		)

internal/tasker/task/account_register.go

@@ -69,7 +69,7 @@ func AccountRegisterOnChainProcessor(cu *custodial.Custodial) func(context.Conte
 				InputData:       input,
 				GasFeeCap:       celoutils.SafeGasFeeCap,
 				GasTipCap:       celoutils.SafeGasTipCap,
-				GasLimit:        gasLimit,
+				GasLimit:        uint64(celoutils.SafeGasLimit),
 				Nonce:           nonce,
 			},
 		)

internal/tasker/task/sign_transfer.go

@@ -78,7 +78,7 @@ func SignTransfer(cu *custodial.Custodial) func(context.Context, *asynq.Task) er
 				InputData:       input,
 				GasFeeCap:       celoutils.SafeGasFeeCap,
 				GasTipCap:       celoutils.SafeGasTipCap,
-				GasLimit:        gasLimit,
+				GasLimit:        uint64(celoutils.SafeGasLimit),
 				Nonce:           nonce,
 			},
 		)

internal/tasker/task/utils.go

@@ -8,8 +8,6 @@ import (
 )
 
 const (
-	gasLimit = 250000
-
 	lockPrefix     = "lock:"
 	lockRetryDelay = 25 * time.Millisecond
 	lockTimeout    = 1 * time.Second