AUTO Value is Created as '0' in Variables

[keeganedwin]

Describe the bug
When creating variables of tokens that use AUTO as a value like in Spacing and lineHeight, the plugin creates them as 0 since variables don't support AUTO as a value. The problem arises when users are trying to bind the AUTO value to text styles but since variables don't support the value it instead applies the 0.

To Reproduce
Steps to reproduce the behavior:

1. Create tokens in spacing and lineHeight with AUTO as the value
2. Create variables of these tokens
3. See error

Expected behavior
We should skip tokens that have AUTO as the value as we cannot create them as the proper variables

Screenshots or Screencasts
https://github.com/tokens-studio/figma-plugin/assets/93133012/d0c7b208-5c75-4c6a-b001-02f7d59d580b

[SamIam4Hyma]

@cuserox tagging you here incase this is related to the work on exporting other items at 0. the AUTO value should be a skipped token on export, it was listed in the dev docs for this @six7 went over in the call.

[six7]

Not sure if the solution is straightforward since variables do not support AUTO. Will need @six7 input on this.

We should skip tokens that have AUTO as the value as we cannot create them