buildx failed with: ERROR: failed to solve: process "/bin/sh -c case \"${TARGETARCH}\" in \t\t'amd64') \t\t\tkubectl_checksum=\"${KUBECTL_CHECKSUM}\"; \t\t;; \t\t'arm64') \t\t\tkubectl_checksum=\"${KUBECTL_CHECKSUM_ARM}\"; \t;; \t\t*) echo >&2 \"error: unsupported architecture ($TARGETARCH)\"; exit 1; ;; \tesac; \tcurl -fsSL \"https://dl.k8s.io/release/${KUBECTL_VERSION}/bin/linux/${TARGETARCH}/kubectl\" -o \"/tmp/kubectl\" \t&& echo \"${kubectl_checksum} /tmp/kubectl\" | sha256sum -c \t&& install -o \"root\" -g \"root\" -m \"0755\" \"/tmp/kubectl\" \"/tmp/local/bin/kubectl\"" did not complete successfully: exit code: 1