Only build linux/amd64 binary

.github/workflows/ci.yml

@@ -36,7 +36,7 @@ jobs:
         name: Create matrix
         id: platforms
         run: |
-          echo ::set-output name=matrix::$(docker buildx bake binary-cross --print | jq -cr '.target."binary-cross".platforms')
+          echo ::set-output name=matrix::'["linux/amd64"]'
       -
         name: Show matrix
         run: |