CI: Add Ubuntu 23.10

(cherry picked from commit 866d4b4127)

.cirrus.yml

@@ -254,6 +254,13 @@ opensuse_tumbleweed_task:
   << : *CI_TEMPLATE
 #  << : *SKIP_TASK_ON_PR
 
+ubuntu23_task:
+  container:
+    # Ubuntu 23.10 EOL: July 2024
+    dockerfile: ci/ubuntu-23.10/Dockerfile
+    << : *RESOURCES_TEMPLATE
+  << : *CI_TEMPLATE
+
 ubuntu22_task:
   container:
     # Ubuntu 22.04 EOL: April 2027

ci/ubuntu-23.10/Dockerfile

@@ -0,0 +1,38 @@
+FROM ubuntu:23.10
+
+ENV DEBIAN_FRONTEND="noninteractive" TZ="America/Los_Angeles"
+
+# A version field to invalidate Cirrus's build cache when needed, as suggested in
+# https://github.com/cirruslabs/cirrus-ci-docs/issues/544#issuecomment-566066822
+ENV DOCKERFILE_VERSION 20230828
+
+RUN apt-get update && apt-get -y install \
+    bc \
+    bison \
+    bsdmainutils \
+    ccache \
+    cmake \
+    curl \
+    flex \
+    g++ \
+    gcc \
+    git \
+    libkrb5-dev \
+    libmaxminddb-dev \
+    libpcap-dev \
+    libssl-dev \
+    make \
+    python3 \
+    python3-dev \
+    python3-pip \
+    python3-websockets \
+    ruby \
+    sqlite3 \
+    swig \
+    unzip \
+    wget \
+    zlib1g-dev \
+  && apt autoclean \
+  && rm -rf /var/lib/apt/lists/*
+
+RUN pip3 install --break-system-packages junit2html