ci: Use containerimages pipeline library

The `buildContainerImage2` function now accepts a `pi` argument, which
controls whether or not the build can run on a Raspberry Pi.  Since the
only reason we were not using this function before was to avoid building
on a Pi, we no longer need the custom code.

ci/Jenkinsfile

@@ -1,70 +1,6 @@
-pipeline {
-    agent none
+@Library('containerimages')_
 
-    stages {
-        stage('Build') {
-            matrix {
-                axes {
-                    axis {
-                        name 'ARCH'
-                        values 'amd64', 'arm64'
-                    }
-                }
-
-                stages {
-                    stage('Build') {
-                        agent {
-                            kubernetes {
-                                yamlFile 'ci/podTemplate.yaml'
-                                yamlMergeStrategy merge()
-                                defaultContainer 'buildah'
-                                nodeSelector "kubernetes.io/arch=${ARCH}"
-                            }
-                        }
-
-                        stages {
-                            stage("Build") {
-                                steps {
-                                    sh '. ci/build.sh'
-                                    stash name: env.ARCH, includes: "*.oci.tar"
-                                }
-                            }
-                        }
-                    }
-                }
-            }
-        }
-
-        stage('Publish') {
-            agent {
-                kubernetes {
-                    yamlFile 'ci/podTemplate.yaml'
-                    yamlMergeStrategy merge()
-                    defaultContainer 'buildah'
-                }
-            }
-
-            environment {
-                REGISTRY_AUTH_FILE = "${env.WORKSPACE_TMP}/auth.json"
-            }
-
-            steps {
-                unstash 'amd64'
-                unstash 'arm64'
-                withCredentials([usernamePassword(
-                    credentialsId: 'jenkins-packages',
-                    usernameVariable: 'BUILDAH_USERNAME',
-                    passwordVariable: 'BUILDAH_PASSWORD',
-                )]) {
-                    sh """
-                        buildah login \
-                        --username \${BUILDAH_USERNAME} \
-                        --password \${BUILDAH_PASSWORD} \
-                        git.pyrocufflink.net
-                    """
-                }
-                sh '. ci/publish.sh'
-            }
-        }
-    }
-}
+buildContainerImage2(
+    archlist: ['amd64', 'arm64'],
+    pi: false,
+)