Bug 1867143 - Upgrade github-sync docker image to Debian 12. r=releng-reviewers,bhearsum

Differential Revision: https://phabricator.services.mozilla.com/D194956

taskcluster/ci/docker-image/kind.yml

@@ -244,7 +244,7 @@ jobs:
         parent: ubuntu1804-test
     github-sync:
         symbol: I(github-sync)
-        parent: debian11-base
+        parent: debian12-base
     sentry:
         symbol: I(sentry)
         parent: debian11-base

taskcluster/docker/github-sync/prepare.sh

@@ -28,4 +28,4 @@ apt-get install -y \
     python3-setuptools
 
 # Python packages
-pip3 install -r "$1"
+pip3 install --break-system-packages -r "$1"