feat(ops/pipelines): trigger tvix buildkite pipeline

Change-Id: I4e81694b9686f977a6590c5e1703a4ef413b0cf4
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8003
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI

ops/pipelines/static-pipeline.yaml

@@ -17,6 +17,16 @@ steps:
     build:
       message: "Verification triggered by ${BUILDKITE_COMMIT}"
 
+  # Run pipeline for tvix when new commits arrive on canon. Since
+  # it is not part of the depot build tree, this is a useful
+  # verification to ensure we don't break external things (too much).
+  - trigger: "tvix"
+    async: true
+    label: ":fork:"
+    branches: "refs/heads/canon"
+    build:
+      message: "Verification triggered by ${BUILDKITE_COMMIT}"
+
   # Create a revision number for the current commit for builds on
   # canon.
   #