[#1341] .golangci.yml: Replace exportloopref with copyloopvar

exportloopref is deprecated.
gopatch:
```
@@
var index, value identifier
var slice expression
@@
for index, value := range slice {
...
-value := value
...
}

@@
var index, value identifier
var slice expression
@@
for index, value := range slice {
...
-index := index
...
}

@@
var value identifier
var channel expression
@@
for value := range channel {
...
-value := value
...
}
```

Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>

pkg/local_object_storage/engine/control.go

@@ -82,8 +82,6 @@ func (e *StorageEngine) Init(ctx context.Context) error {
 	}
 
 	for id, sh := range e.shards {
-		id := id
-		sh := sh
 		eg.Go(func() error {
 			if err := sh.Init(ctx); err != nil {
 				errCh <- shardInitError{

pkg/local_object_storage/engine/shards.go

@@ -367,7 +367,6 @@ func (e *StorageEngine) closeShards(deletedShards []hashedShard) error {
 	var multiErrGuard sync.Mutex
 	var eg errgroup.Group
 	for _, sh := range deletedShards {
-		sh := sh
 		eg.Go(func() error {
 			err := sh.SetMode(mode.Disabled)
 			if err != nil {

pkg/local_object_storage/engine/writecache.go

@@ -102,7 +102,6 @@ func (e *StorageEngine) SealWriteCache(ctx context.Context, prm SealWriteCachePr
 
 	eg, egCtx := errgroup.WithContext(ctx)
 	for _, shardID := range prm.ShardIDs {
-		shardID := shardID
 		eg.Go(func() error {
 			e.mtx.RLock()
 			sh, ok := e.shards[shardID.String()]