buildx failed with: ERROR: failed to solve: process "/bin/sh -c CGO_ENABLED=0 GOOS=linux GOARCH=${GOARCH} go build -a -o gardener-extension-provider-metal ./cmd/gardener-extension-provider-metal/main.go && CGO_ENABLED=0 GOOS=linux GOARCH=${GOARCH} go build -a -o gardener-extension-admission-metal ./cmd/gardener-extension-admission-metal/main.go" did not complete successfully: exit code: 1