Update Dockerfile

Dockerfile

@@ -2,6 +2,7 @@ FROM ubuntu:bionic as backend
 
 # Install necessary packages for the backend server
 RUN apt-get update && \
+    apt-get upgrade -y && \
     apt-get install -y libglu1 xvfb libxcursor1 net-tools
 
 # Copy backend server files
@@ -17,9 +18,11 @@ RUN chmod +x /app/build/tanks.x86_64 && \
     mkdir -p /var/log/nginx /var/lib/nginx && \
     chown -R www-data:www-data /var/log/nginx /var/lib/nginx /app /usr/share/nginx/html /usr/share/nginx/html-page
 
-# Install Nginx
+# Install Nginx and dependencies
 RUN apt-get update && \
-    apt-get install -y nginx
+    apt-get install -y nginx && \
+    apt-get clean && \
+    rm -rf /var/lib/apt/lists/*
 
 # Set workdir
 WORKDIR /app/