accounts/abi/bind: add const for tx fee elasticity multiplier (#25504)

Co-authored-by: Felix Lange <fjl@twurst.com>
Co-authored-by: rjl493456442 <garyrong0905@gmail.com>

accounts/abi/bind/base.go

@@ -32,6 +32,8 @@ import (
 	"github.com/ethereum/go-ethereum/event"
 )
 
+const basefeeWiggleMultiplier = 2
+
 // SignerFn is a signer function callback when a contract requires a method to
 // sign the transaction before submission.
 type SignerFn func(common.Address, *types.Transaction) (*types.Transaction, error)
@@ -254,7 +256,7 @@ func (c *BoundContract) createDynamicTx(opts *TransactOpts, contract *common.Add
 	if gasFeeCap == nil {
 		gasFeeCap = new(big.Int).Add(
 			gasTipCap,
-			new(big.Int).Mul(head.BaseFee, big.NewInt(2)),
+			new(big.Int).Mul(head.BaseFee, big.NewInt(basefeeWiggleMultiplier)),
 		)
 	}
 	if gasFeeCap.Cmp(gasTipCap) < 0 {