syz-cluster: set workflow step retry strategy

When a triage or build step coincides with a cron job that polls new
kernel trees, they often fail due to git command noticing that the
repository is being updated.

In this case, the step logs an error and exits with status=1. Argo
workflows offers a functionality to retry such steps up to the specific
number of times and with exponentially increasing backoffs.

Configure the build and triage step templates to retry 3 times with 5
and then 10 minutes distance between the retries.

Author: a-nogikh

syz-cluster/workflow/build-step/workflow-template.yaml

@@ -8,6 +8,10 @@ metadata:
 spec:
   templates:
     - name: build-step
+      retryStrategy:
+        limit: "3"
+        backoff:
+          duration: "5m"
       inputs:
         parameters:
           - name: findings

syz-cluster/workflow/triage-step/workflow-template.yaml

@@ -8,6 +8,10 @@ metadata:
 spec:
   templates:
     - name: triage-step
+      retryStrategy:
+        limit: "3"
+        backoff:
+          duration: "5m"
       initContainers:
         - name: setup-overlays
           image: alpine/git:latest