Update Terraform and MixinExtras for compatibility buffs.

- Minor compatibility improvements

Author: gniftygnome

gradle.properties

@@ -10,10 +10,10 @@ loader_version=0.14.19
 fabric_version=0.77.0+1.19.4
 
 # Terraform modules
-terraform_biome_remapper_api_version=6.1.2
-terraform_shapes_api_version=6.1.2
-terraform_surfaces_api_version=6.1.2
-terraform_wood_api_version=6.1.2
+terraform_biome_remapper_api_version=6.1.3
+terraform_shapes_api_version=6.1.3
+terraform_surfaces_api_version=6.1.3
+terraform_wood_api_version=6.1.3
 
 # Biolith for worldgen module and testing
 # WARNING: Do not change this in 1.19.4. This is the special version for TerraBlender generation.