[ci] remove old prepare_docker
diff --git a/.buildkite/core.rayci.yml b/.buildkite/core.rayci.yml
index e2bee4c6d3983..0cc3c37327d41 100644
--- a/.buildkite/core.rayci.yml
+++ b/.buildkite/core.rayci.yml
@@ -270,7 +270,6 @@ steps:
     instance_type: medium
     commands:
       - bazel run //ci/ray_ci:build_in_docker -- docker --python-version 3.8 --platform cpu --canonical-tag ha_integration
-      - docker tag rayproject/ray:ha_integration ray_ci:v1
       - bazel run //ci/ray_ci:test_in_docker -- //python/ray/tests/... core --only-tags ha_integration
     depends_on:
       - manylinux
diff --git a/.buildkite/serve.rayci.yml b/.buildkite/serve.rayci.yml
index e0cc9d3f2d541..555151b7eebae 100644
--- a/.buildkite/serve.rayci.yml
+++ b/.buildkite/serve.rayci.yml
@@ -154,7 +154,6 @@ steps:
     instance_type: medium
     commands:
       - bazel run //ci/ray_ci:build_in_docker -- docker --python-version 3.8 --platform cpu --canonical-tag ha_integration
-      - docker tag rayproject/ray:ha_integration ray_ci:v1
       - bazel run //ci/ray_ci:test_in_docker -- //python/ray/serve/tests/... serve
         --only-tags ha_integration
     depends_on:
diff --git a/ci/ci.sh b/ci/ci.sh
index 6aedb17507d55..8cfe4df863567 100755
--- a/ci/ci.sh
+++ b/ci/ci.sh
@@ -177,35 +177,6 @@ test_core() {
   bazel test --config=ci --build_tests_only $(./ci/run/bazel_export_options) -- "${args[@]}"
 }
 
-prepare_docker() {
-    rm "${WORKSPACE_DIR}"/python/dist/* ||:
-    pushd "${WORKSPACE_DIR}/python"
-    pip install -e . --verbose
-    python setup.py bdist_wheel
-    tmp_dir="/tmp/prepare_docker_$RANDOM"
-    mkdir -p $tmp_dir
-    cp "${WORKSPACE_DIR}"/python/dist/*.whl $tmp_dir
-    wheel=$(ls "${WORKSPACE_DIR}"/python/dist/)
-    base_image=$(python -c "import sys; print(f'rayproject/ray-deps:nightly-py{sys.version_info[0]}{sys.version_info[1]}-cpu')")
-    echo "
-    FROM $base_image
-
-    ENV LC_ALL=C.UTF-8
-    ENV LANG=C.UTF-8
-    COPY ./*.whl /
-    EXPOSE 8000
-    EXPOSE 10001
-    RUN pip install /${wheel}[serve]
-    RUN (sudo apt update || true) && sudo apt install curl -y
-    " > $tmp_dir/Dockerfile
-
-    pushd $tmp_dir
-    docker build . -t ray_ci:v1
-    popd
-
-    popd
-}
-
 # For running Serve tests on Windows.
 test_serve() {
   if [ "${OSTYPE}" = msys ]; then
diff --git a/python/ray/tests/conftest_docker.py b/python/ray/tests/conftest_docker.py
index aae45ec68d18d..914f19732ff79 100644
--- a/python/ray/tests/conftest_docker.py
+++ b/python/ray/tests/conftest_docker.py
@@ -80,7 +80,7 @@ def print_logs(self):
 head_node_container_name = "gcs" + str(int(time.time()))
 
 head_node = container(
-    image="ray_ci:v1",
+    image="rayproject/ray:ha_integration",
     name=head_node_container_name,
     network="{gcs_network.name}",
     command=[
@@ -111,7 +111,7 @@ def print_logs(self):
 )
 
 worker_node = container(
-    image="ray_ci:v1",
+    image="rayproject/ray:ha_integration",
     network="{gcs_network.name}",
     command=[
         "ray",

and directly tag images as `ha_integration`
