Rename rockylinux9 build directory to rocky9

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

rocky9/build.sh

@@ -0,0 +1,20 @@
+#!/bin/sh
+
+set -eu
+
+IMAGE_NAME="${IMAGE_NAME:-rocky9-source-stack}"
+SCRIPT_DIR=$(CDPATH= cd -- "$(dirname -- "$0")" && pwd)
+
+if [ -n "${CONTAINER_ENGINE:-}" ]; then
+    ENGINE=$CONTAINER_ENGINE
+elif command -v docker >/dev/null 2>&1; then
+    ENGINE=docker
+elif command -v podman >/dev/null 2>&1; then
+    ENGINE=podman
+else
+    echo "Error: Docker or Podman is required." >&2
+    exit 1
+fi
+
+echo "Building image $IMAGE_NAME with $ENGINE ..."
+exec "$ENGINE" build --tag "$IMAGE_NAME" "$SCRIPT_DIR"