try to fix test with 0.12.5

Dockerfile

@@ -10,7 +10,7 @@ FROM concourse/golang-builder AS builder
   RUN go build -o /assets/task ./cmd/task
   RUN go build -o /assets/build ./cmd/build
 
-FROM moby/buildkit:v0.12.4 AS task
+FROM moby/buildkit:v0.12.5 AS task
   COPY --from=builder /assets/task /usr/bin/
   COPY --from=builder /assets/build /usr/bin/
   COPY bin/setup-cgroups /usr/bin/

scripts/setup-buildkit.sh

@@ -1,5 +1,5 @@
 if ! which buildctl >/dev/null || ! which buildkitd >/dev/null; then
-  BUILDKIT_VERSION=0.12.4
+  BUILDKIT_VERSION=0.12.5
   BUILDKIT_URL=https://github.com/moby/buildkit/releases/download/v$BUILDKIT_VERSION/buildkit-v$BUILDKIT_VERSION.linux-amd64.tar.gz
 
   curl -fL "$BUILDKIT_URL" | tar zxf -

task_test.go

@@ -342,6 +342,7 @@ func (s *TaskSuite) TestImageArgs() {
 
 	s.req.Config.ContextDir = "testdata/image-args"
 	s.req.Config.AdditionalTargets = []string{"first"}
+	s.req.Config.ImagePlatform = "linux/amd64"
 	s.req.Config.ImageArgs = []string{
 		"first_image=" + firstPath,
 		"second_image=" + secondPath,