remove 386 build

Author: ryansheehan

.github/workflows/build-vanilla.yml

@@ -31,7 +31,7 @@ jobs:
         with:
           context: ./vanilla
           file: vanilla/Dockerfile
-          platforms: linux/386,linux/amd64,linux/arm/v7,linux/arm64,linux/ppc64le
+          platforms: linux/amd64,linux/arm/v7,linux/arm64,linux/ppc64le
           push: true
           tags: |
             ryshe/terraria:vanilla-latest