chore: upgrade dockerfile ubuntu version

Dockerfile

@@ -1,4 +1,4 @@
-FROM ubuntu:focal
+FROM ubuntu:noble
 SHELL ["/bin/bash", "-c"]
 
 ARG python_version=3.8
@@ -15,7 +15,7 @@ RUN pip install virtualenv
 
 # Define Environment Variables
 ENV CODEJAIL_GROUP=sandbox
-ENV CODEJAIL_SANDBOX_CALLER=ubuntu
+ENV CODEJAIL_SANDBOX_CALLER=codejail
 ENV CODEJAIL_TEST_USER=sandbox
 ENV CODEJAIL_TEST_VENV=/home/sandbox/codejail_sandbox-python${python_version}
 
@@ -33,8 +33,8 @@ RUN addgroup $CODEJAIL_GROUP
 RUN adduser --disabled-login --disabled-password $CODEJAIL_TEST_USER --ingroup $CODEJAIL_GROUP
 
 # Switch to non root user inside Docker container
-RUN addgroup ubuntu
-RUN adduser --disabled-login --disabled-password ubuntu --ingroup ubuntu
+RUN addgroup $CODEJAIL_SANDBOX_CALLER
+RUN adduser --disabled-login --disabled-password $CODEJAIL_SANDBOX_CALLER --ingroup $CODEJAIL_SANDBOX_CALLER
 
 # Give Ownership of sandbox env to sandbox group and user
 RUN chown -R $CODEJAIL_TEST_USER:$CODEJAIL_GROUP $CODEJAIL_TEST_VENV
@@ -61,7 +61,7 @@ COPY sudoers-file/01-sandbox-python-${python_version} /etc/sudoers.d/01-sandbox
 RUN chmod 0440 /etc/sudoers.d/01-sandbox
 
 # Change Repo ownership
-RUN chown -R ubuntu:ubuntu ../codejail
+RUN chown -R $CODEJAIL_SANDBOX_CALLER:$CODEJAIL_SANDBOX_CALLER ../codejail
 
 # Switch to ubuntu user
-USER ubuntu
+USER $CODEJAIL_SANDBOX_CALLER