feat: push docker images to GAR repository

This is to support the migration to Mozcloud. We'll do this in parallel with pushes to dockerhub to avoid one pipeline busting the other.

I've dropped support for the archive tags here, because as far as I know we've never made use of them.

Author: bhearsum

taskcluster/kinds/push-image-gar/kind.yml

@@ -0,0 +1,73 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+---
+
+loader: taskgraph.loader.transform:loader
+
+kind-dependencies:
+    - docker-image
+
+transforms:
+    - taskgraph.transforms.task_context
+    - taskgraph.transforms.run
+    - taskgraph.transforms.task
+
+task-defaults:
+    description: Push {name} {docker_tag} docker image to GAR
+    worker-type: images
+    task-context:
+        from-parameters:
+            head_rev: head_rev
+            head_repo: head_repository
+            docker_tag: docker_tag
+            moz_build_date: moz_build_date
+        substitution-fields:
+            - description
+            - dependencies.image
+            - worker.env
+            - run-on-git-branches
+    dependencies:
+        image: docker-image-{name}
+    worker:
+        taskcluster-proxy: true
+        docker-image: {in-tree: skopeo}
+        max-run-time: 1800
+        env:
+            VCS_HEAD_REPOSITORY: "{head_repo}"
+            APP: "{name}"
+            DOCKER_REPO: "{name}"
+            VCS_HEAD_REV: "{head_rev}"
+            DOCKER_TAG: "{docker_tag}"
+    run-on-tasks-for: [github-push]
+    run-on-git-branches:
+        - ^dev$
+        - ^production$
+        - ^dev-{name}$
+        - ^production-{name}$
+    run:
+        using: run-task
+        checkout: false
+        command:
+            - /usr/local/bin/push_image_gar.sh
+    fetches:
+        image:
+            - artifact: image.tar.zst
+              extract: false
+    scopes:
+        - secrets:get:project/releng/scriptworker-scripts/deploy
+
+tasks:
+    addonscript: {}
+    balrogscript: {}
+    bitrisescript: {}
+    beetmoverscript: {}
+    bouncerscript: {}
+    githubscript: {}
+    landoscript: {}
+    pushapkscript: {}
+    pushflatpakscript: {}
+    pushmsixscript: {}
+    shipitscript: {}
+    signingscript: {}
+    treescript: {}