Ignore lint on indirectly used variable

Author: Bryan Johnson

src/scripts/docker_buildx.sh

@@ -13,6 +13,7 @@ AWS_ECR_EVAL_DOCKERFILE="$(eval echo "${AWS_ECR_STR_DOCKERFILE}")"
 AWS_ECR_EVAL_PROFILE_NAME="$(eval echo "${AWS_ECR_STR_PROFILE_NAME}")"
 AWS_ECR_EVAL_PLATFORM="$(eval echo "${AWS_ECR_STR_PLATFORM}")"
 AWS_ECR_EVAL_LIFECYCLE_POLICY_PATH="$(eval echo "${AWS_ECR_STR_LIFECYCLE_POLICY_PATH}")"
+# shellcheck disable=SC2034 # used indirectly via environment in `docker buildx` builds
 BUILDX_NO_DEFAULT_ATTESTATIONS=1