updatebot: Updates for latest version

The latest version of `updatebot` has two major changes:

1. Projects can encompass multiple images, eliminating the need for
   multiple configuration files and CronJobs.  Projects are now defined
   in a YAML documen, since the data structure is very nested and is
   cumbersome to express in TOML.
2. Pull requests can now include a diff of the resources that will
   change if the PR is merged.  This requires the `kubectl` and `diff`
   programs (which are not currently included in the _updatebot_
   container image, so we bind-mount them from the host) and permission
   to compare the local manifests using the Kubernetes API.  Oddly,
   computing the diff requires permission to use the PATCH method, even
   though the client is not requesting any changes.  This is apparently
   a long-standing bug ([issue #981][0]) that may or may not ever be
   fixed.

[0]: https://github.com/kubernetes/kubectl/issues/981

updatebot/config.yml

@@ -0,0 +1,71 @@
+repo:
+  url: https://git.pyrocufflink.net/infra/kubernetes
+  token_file: /run/secrets/updatebot/gitea.token
+
+projects:
+- name: home-assistant
+  kind: kustomize
+  images:
+  - name: home-assistant
+    image: ghcr.io/home-assistant/home-assistant
+    source:
+      kind: github
+      organization: home-assistant
+      repo: core
+  - name: whisper
+    image: docker.io/rhasspy/wyoming-whisper
+    source:
+      kind: docker
+      namespace: rhasspy
+      repository: wyoming-whisper
+  - name: piper
+    image: docker.io/rhasspy/wyoming-piper
+    source:
+      kind: docker
+      namespace: rhasspy
+      repository: wyoming-piper
+  - name: zigbee2mqtt
+    image: docker.io/koenkk/zigbee2mqtt
+    source:
+      kind: github
+      organization: Koenkk
+      repo: zigbee2mqtt
+  - name: zwavejs2mqtt
+    image: docker.io/zwavejs/zwave-js-ui
+    source:
+      kind: github
+      organization: zwave-js
+      repo: zwave-js-ui
+
+- name: firefly-iii
+  kind: kustomize
+  images:
+  - name: firefly-iii
+    image: docker.io/fireflyiii/core
+    tag_format: version-{version}
+    source:
+      kind: github
+      organization: firefly-iii
+      repo: firefly-iii
+
+- name: paperless-ngx
+  kind: kustomize
+  images:
+  - name: paperless-ngx
+    image: ghcr.io/paperless-ngx/paperless-ngx
+    source:
+      kind: github
+      organization: paperless-ngx
+      repo: paperless-ngx
+  - name: gotenberg
+    image: docker.io/gotenberg/gotenberg
+    source:
+      kind: github
+      organization: gotenberg
+      repo: gotenberg
+  - name: tika
+    image: docker.io/apache/tika
+    source:
+      kind: docker
+      namespace: apache
+      repository: tika