Remove redundant sync.Mutex from FeeParameters

Author: m-Peter

storage/pebble/fee_parameters.go

@@ -4,7 +4,6 @@ import (
 	"errors"
 	"fmt"
 	"slices"
-	"sync"
 
 	"github.com/cockroachdb/pebble"
 	"github.com/ethereum/go-ethereum/rlp"
@@ -17,7 +16,6 @@ var _ storage.FeeParametersIndexer = &FeeParameters{}
 
 type FeeParameters struct {
 	store *Storage
-	mu    sync.Mutex
 }
 
 func NewFeeParameters(store *Storage) *FeeParameters {