Restore the base scale value in spacing tokens

@gsouquet IIRC, you had to rename some spacing tokens to mitigate some bugs for the Tokens Studio Style Dictionary transforms.

For example, the value for for `6x` should be `{space.scale} * 6` instead of `24`.

```
"5x": {
"value": "{space.scale} * 5",
"type": "spacing"
},
"6x": {
"value": "24",
"type": "spacing"
},
```

I'm creating this issue to keep track of this temporary workaround, so that we can revert it once the token transformation library has been fixed.

```[tasklist]
### Blocked on
- [ ] https://github.com/tokens-studio/sd-transforms/issues/13
- [ ] https://github.com/tokens-studio/sd-transforms/issues/121
```