build: use ASP.NET runtime for backend images

ci/release-linux.sh

@@ -63,7 +63,11 @@ publish_aot() {
 publish_aot agent agent/src/Monitor.Agent "$output/agent"
 publish_aot probe probe/src/Monitor.Probe "$output/probe"
 publish_aot fleet-enroll fleet/tools/fleet-enroll "$output/fleet-enroll"
-publish_aot backend src/Monitor.Backend "$output/backend"
+(cd "$root/backend" && dotnet publish src/Monitor.Backend \
+  -c Release --no-self-contained \
+  -p:UseAppHost=false -p:OpenApiGenerateDocuments=false \
+  --artifacts-path "$build_root" \
+  -o "$output/backend")
 
 package_node() {
   local role="$1" stage="$stage_root/$1"
@@ -112,8 +116,8 @@ upload_package() {
 package_node agent
 package_node probe
 
-# The .NET runtime-deps image is a multi-arch OCI base. The Containerfile does
-# not execute target-platform commands, so Buildah can assemble either image.
+# The ASP.NET runtime image is multi-arch. The Containerfile does not execute
+# target-platform commands, so Buildah can assemble either image.
 container_context="$root/.release/container/linux-$arch"
 mkdir -p "$container_context/app" "$container_context/data"
 cp -a "$output/backend/." "$container_context/app/"