Bug 1766948 - Add cargo to the Updatebot Docker image r=jewilde

Differential Revision: https://phabricator.services.mozilla.com/D145127

taskcluster/ci/updatebot/kind.yml

@@ -6,6 +6,7 @@ loader: gecko_taskgraph.loader.transform:loader
 
 kind-dependencies:
     - fetch
+    - toolchain
 
 transforms:
     - gecko_taskgraph.transforms.release_notifications:transforms
@@ -70,6 +71,9 @@ jobs:
                 - on-failed
                 - on-exception
             emails: ["tom@mozilla.com", "jewilde@mozilla.com"]
+        fetches:
+            toolchain:
+                - linux64-rust
 
     cron-win:
         description: Cron Job for Updatebot (Windows)

taskcluster/docker/updatebot/Dockerfile

@@ -16,6 +16,6 @@ ENV     SHELL               /bin/bash
 ENV     USER                worker
 ENV     LOGNAME             worker
 ENV     PYTHONUNBUFFERED    1
-ENV     PATH                "/builds/worker/go/bin:${PATH}"
+ENV     PATH                "/builds/worker/go/bin:/builds/worker/fetches/rustc/bin:${PATH}"
 
 RUN     cd /builds/worker && ./setup.sh