[#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>

cmd/frostfs-adm/internal/modules/morph/generate/generate.go

@@ -73,7 +73,6 @@ func initializeWallets(v *viper.Viper, walletDir string, size int) ([]string, er
 			return nil, fmt.Errorf("can't fetch password: %w", err)
 		}
 
-		i := i
 		errG.Go(func() error {
 			p := filepath.Join(walletDir, innerring.GlagoliticLetter(i).String()+".json")
 			f, err := os.OpenFile(p, os.O_CREATE, 0o644)
@@ -107,7 +106,6 @@ func initializeWallets(v *viper.Viper, walletDir string, size int) ([]string, er
 	// Create consensus account with 2*N/3+1 multi-signature.
 	bftCount := smartcontract.GetDefaultHonestNodeCount(size)
 	for i := range wallets {
-		i := i
 		ps := pubs.Copy()
 		errG.Go(func() error {
 			if err := addMultisigAccount(wallets[i], majCount, constants.CommitteeAccountName, passwords[i], ps); err != nil {