for latest VS Code theme, highlight_theme_info() return many same results

```lua
local a = tm.highlight_theme_info()
source = {a[1], a[2], a[3]}
type = {a[22], a[23], a[24]}
struct = {a[25], a[26], a[27]}
control = {a[28], a[29], a[30]}
```

For all vscode builtin themes, `type, struct, control` always be same. Except `Red`, `source` are same as them. Is it a bug?