style(parser): range over the include chain depth

Assisted-by: GLM 5.3

parser/preproc_test.go

@@ -502,7 +502,7 @@ func TestSelfIncludeIsDetected(t *testing.T) {
 func TestDeepIncludeChainCompletes(t *testing.T) {
 	const depth = 2000
 	dir := t.TempDir()
-	for i := 0; i < depth; i++ {
+	for i := range depth {
 		var content string
 		if i == depth-1 {
 			content = "#define DEEPEST $7\n"