Bug 1762037 - Update the lint docker image from Ubuntu 18.04 to Debian 11 r=linter-reviewers,ahal

Differential Revision: https://phabricator.services.mozilla.com/D142376

taskcluster/ci/docker-image/kind.yml

@@ -108,7 +108,7 @@ jobs:
             - deb11-valgrind
     lint:
         symbol: I(lnt)
-        parent: ubuntu1804-base
+        parent: debian11-base
     # Neither the debian10-raw nor the debian10-packages images can have
     # packages dependencies.
     debian10-raw:

taskcluster/docker/lint/system-setup.sh

@@ -12,9 +12,8 @@ apt_packages+=('curl')
 apt_packages+=('iproute2')
 apt_packages+=('locales')
 apt_packages+=('graphviz')
-apt_packages+=('python')
-apt_packages+=('python-pip')
 apt_packages+=('python3-pip')
+apt_packages+=('python-is-python3')
 apt_packages+=('shellcheck')
 apt_packages+=('sudo')
 apt_packages+=('wget')