Update pipeline.yaml

Author: ggilmore

.buildkite/pipeline.yaml

@@ -13,14 +13,14 @@ steps:
   - wait
 
   - label: ":pulumi: :k8s:"
-    concurrency: 2
+    concurrency: 3
     concurrency_group: deploy-sourcegraph/integration
     command: .buildkite/integration-test.sh
     env:
       VERBOSE: "true"
 
   - label: ":k8s:"
-    concurrency: 2
+    concurrency: 3
     concurrency_group: deploy-sourcegraph/integration-restricted
     command: .buildkite/integration-restricted-test.sh