feat: Add Python 3.13 to testing image

Author: parthea

.kokoro/docker/Dockerfile

@@ -14,7 +14,7 @@
 
 # We want to use LTS ubuntu from our mirror because dockerhub has a
 # rate limit.
-FROM mirror.gcr.io/library/ubuntu:20.04
+FROM mirror.gcr.io/library/ubuntu:24.04
 
 ENV DEBIAN_FRONTEND noninteractive
 
@@ -28,6 +28,7 @@ ENV LANG C.UTF-8
 
 # Install dependencies.
 RUN apt-get update \
+  && apt -y upgrade \
   && apt-get install -y --no-install-recommends \
   apt-transport-https \
   build-essential \
@@ -115,7 +116,7 @@ RUN set -ex \
   && export GNUPGHOME="$(mktemp -d)" \
   && echo "disable-ipv6" >> "${GNUPGHOME}/dirmngr.conf" \
   && /tmp/fetch_gpg_keys.sh \
-  && for PYTHON_VERSION in 2.7.18 3.7.17 3.8.18 3.9.18 3.10.13 3.11.6 3.12.0; do \
+  && for PYTHON_VERSION in 2.7.18 3.7.17 3.8.20 3.9.20 3.10.15 3.11.10 3.12.7 3.13.0; do \
   wget --no-check-certificate -O python-${PYTHON_VERSION}.tar.xz "https://www.python.org/ftp/python/${PYTHON_VERSION%%[a-z]*}/Python-$PYTHON_VERSION.tar.xz" \
   && wget --no-check-certificate -O python-${PYTHON_VERSION}.tar.xz.asc "https://www.python.org/ftp/python/${PYTHON_VERSION%%[a-z]*}/Python-$PYTHON_VERSION.tar.xz.asc" \
   && gpg --batch --verify python-${PYTHON_VERSION}.tar.xz.asc python-${PYTHON_VERSION}.tar.xz \
@@ -155,6 +156,7 @@ RUN wget --no-check-certificate -O /tmp/get-pip.py 'https://bootstrap.pypa.io/ge
   && [ "$(pip list |tac|tac| awk -F '[ ()]+' '$1 == "pip" { print $2; exit }')" = "$PYTHON_PIP_VERSION" ]
 
 # Ensure Pip for all python3 versions
+RUN python3.13 /tmp/get-pip.py
 RUN python3.12 /tmp/get-pip.py
 RUN python3.11 /tmp/get-pip.py
 RUN python3.9 /tmp/get-pip.py
@@ -170,15 +172,17 @@ RUN python3.9 -m pip
 RUN python3.10 -m pip
 RUN python3.11 -m pip
 RUN python3.12 -m pip
+RUN python3.13 -m pip
 
 # Install "setuptools" for Python 3.12+ (see https://docs.python.org/3/whatsnew/3.12.html#distutils)
 RUN python3.12 -m pip install --no-cache-dir setuptools
+RUN python3.13 -m pip install --no-cache-dir setuptools
 
 # Install "virtualenv", since the vast majority of users of this image will want it.
 RUN pip install --no-cache-dir virtualenv
 
 # Setup Cloud SDK
-ENV CLOUD_SDK_VERSION 389.0.0
+ENV CLOUD_SDK_VERSION 502.0.0
 # Use system python for cloud sdk.
 ENV CLOUDSDK_PYTHON python3.10
 RUN wget https://dl.google.com/dl/cloudsdk/channels/rapid/downloads/google-cloud-sdk-$CLOUD_SDK_VERSION-linux-x86_64.tar.gz