documentation: use server-side apply in README (#3326)

* docs: update Spark operator installation command to include --force-conflicts

Signed-off-by: Denyme24 <[email protected]>

* update README

Signed-off-by: Denyme24 <[email protected]>

* update README

Signed-off-by: Denyme24 <[email protected]>

---------

Signed-off-by: Denyme24 <[email protected]>

Author: Denyme24

README.md

@@ -566,7 +566,7 @@ kustomize build applications/trainer/upstream/overlays/kubeflow-platform | kubec
 Install the Spark Operator:
 
 ```sh
-kustomize build applications/spark/spark-operator/overlays/kubeflow | kubectl apply -f -
+kustomize build applications/spark/spark-operator/overlays/kubeflow | kubectl apply --server-side --force-conflicts -f -
 ```
 
 **Note:** The Ray component in the experimental folder is configured to disable Istio sidecar injection for its head and worker pods to ensure compatibility with Istio CNI.

tests/spark_install.sh

@@ -5,7 +5,7 @@ REPOSITORY_ROOT=$(git rev-parse --show-toplevel 2>/dev/null || echo "${GITHUB_WO
 cd "${REPOSITORY_ROOT}"
 
 # Install Spark operator
-kustomize build applications/spark/spark-operator/overlays/standalone | kubectl -n kubeflow apply --server-side -f -
+kustomize build applications/spark/spark-operator/overlays/kubeflow | kubectl -n kubeflow apply --server-side --force-conflicts -f -
 
 # Wait for the operator controller to be ready.
 kubectl -n kubeflow wait --for=condition=available --timeout=60s deploy/spark-operator-controller