Initial pass on Antithesis testing

This adds a "limbo_stress" tool for stress testing Limbo in
non-deterministic way together with support code to run the tests under
Antithesis (which makes them deterministic). The stress tester does not
really do anything useful yet, this is just a step to make sure we can
run tests under Antithesis.

scripts/antithesis/publish-docker.sh

@@ -0,0 +1,23 @@
+#!/bin/sh
+
+set -e
+
+if [ -z "$DOCKER_REPO_URL" ]; then
+    echo "Error: DOCKER_REPO_URL is not set."
+    exit 1
+fi
+
+if [ -z "$IMAGE_NAME" ]; then
+    echo "Error: IMAGE_NAME is not set."
+    exit 1
+fi
+
+if [ -z "$DOCKER_IMAGE_VERSION" ]; then
+    DOCKER_IMAGE_VERSION=$(git rev-parse HEAD)
+fi
+
+DOCKER_IMAGE=$DOCKER_REPO_URL/$IMAGE_NAME:$DOCKER_IMAGE_VERSION
+
+docker build -f $DOCKERFILE -t $DOCKER_IMAGE $DOCKER_BUILD_ARGS $DOCKER_DIR
+
+docker push $DOCKER_IMAGE