fix: don't sample traces on the exporter (#4822)

It generates a new sub-span for every GCS upload, which is too many

Author: michaelkedar

deployment/clouddeploy/gke-workers/base/exporter.yaml

@@ -33,5 +33,5 @@ spec:
                 memory: "64Gi"
             env:
               - name: TRACE_SAMPLE_RATE
-                value: "1.0"
+                value: "0.0"
           restartPolicy: Never