fix dockerfile to use fixed commit and ubuntu ver

Dockerfile

@@ -1,4 +1,6 @@
-FROM ubuntu:latest
+ARG UBUNTU_VERSION="noble"
+
+FROM ubuntu:${UBUNTU_VERSION}
 
 ARG BUILD_SERVER_NAME="services.lame-network.local"
 
@@ -14,6 +16,10 @@ WORKDIR /tmp
 
 RUN git clone https://github.com/anope/anope.git
 
+WORKDIR /tmp/anope 
+
+RUN git checkout 2.1
+
 WORKDIR /tmp/anope/modules
 
 RUN ls -1 extra/*.cpp | xargs -i ln -s {}