Fix error CS0414: The field 'TMP_FontAsset.fontWeights' is assigned but its value is never used

Steps to reproduce:

1. Make a player build 
2. Notice the build error

Actual results: 

This error prevents the player to build successfully

Expected results: 

We should be able to build successfully

Reproducible with versions: trunk, 6000.5.0a6

Not reproducible with versions: 

Can’t test with versions: 

Tested on (OS):