Update Dockerfile

Dockerfile

@@ -14,8 +14,9 @@ USER user
 # Set the working directory
 WORKDIR /home/user
 
-# Add a script to switch to root and execute a command
-RUN echo 'echo "user" | su -c "echo Sudo is not working but su is!"' > /home/user/test.sh && \
+# Add a script with the correct shebang
+RUN echo -e '#!/bin/bash\n' > /home/user/test.sh && \
+    echo 'echo "user" | su -c "echo Sudo is not working but su is!"' >> /home/user/test.sh && \
     chmod +x /home/user/test.sh
 
 # Run the test script