Use amd64 for Docker images by default

cli/cmd/docker/agent.go

@@ -243,6 +243,7 @@ func (a *Agent) getPullOptions(image string) (types.ImagePullOptions, error) {
 
 	return types.ImagePullOptions{
 		RegistryAuth: authConfigEncoded,
+		Platform:     "linux/amd64",
 	}, nil
 }
 

cli/cmd/docker/builder.go

@@ -71,7 +71,8 @@ func (a *Agent) BuildLocal(opts *BuildOpts) error {
 		CacheFrom: []string{
 			fmt.Sprintf("%s:%s", opts.ImageRepo, opts.CurrentTag),
 		},
-		Remove: true,
+		Remove:   true,
+		Platform: "linux/amd64",
 	})
 
 	if err != nil {