*: fix copyloopvar warnings

Go 1.22+ allows to drop these:

  The copy of the 'for' variable "i" can be deleted (Go 1.22+) (copyloopvar)

Signed-off-by: Roman Khimov <roman@nspcc.ru>

pkg/network/server_test.go

@@ -218,7 +218,6 @@ func testGetBlocksByIndex(t *testing.T, cmd CommandType) {
 	expectsCmd := make([]CommandType, 10)
 	expectedHeight := make([][]uint32, 10)
 	for i := range ps {
-		i := i
 		ps[i] = newLocalPeer(t, s)
 		ps[i].messageHandler = func(t *testing.T, msg *Message) {
 			require.Equal(t, expectsCmd[i], msg.Command)

pkg/vm/vm_test.go

@@ -594,7 +594,6 @@ func TestJMPs(t *testing.T) {
 	}
 
 	for i, tc := range testCases {
-		i := i
 		t.Run(tc.name, func(t *testing.T) {
 			for op := opcode.JMP; op < opcode.JMPLEL; op++ {
 				resOp := op