fix(wrong card playable)

[Vito0912]

Description

Resolved an issue where the SwapCarrots card could be played when it shouldn't have been allowed.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

How Has This Been Tested?

I played several rounds, and the error reported on Discord did not occur. However, I did not specifically test for that particular issue as I found no way of creating a game that has this condition.

What Has Been Changed?

Added a constant lettuce position (as it does not change). And fixed the condition in which when a player was on a lattuce the check was okay but it should report that it was not

Checklist:

• My code follows the style guidelines of this project (hopefully)
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas (self-explaining)
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[maxblan]

Thank you very much for your work!
The only suggestion I have is to put the lettuce index constant into the constants.rs.
I will do this myself to speed up the process.