Do not fail the build in teardown failures

Author: nkammah

.buildkite/build_pr_pipeline.yml

@@ -12,7 +12,7 @@ steps:
     agents:
       provider: "gcp"
       image: family/docs-ubuntu-2204
-  - command: .buildkite/scripts/build_pr_teardown.sh
+  - command: ".buildkite/scripts/build_pr_teardown.sh || true"
     label: "teardown"
     depends_on:
       - step: "build-pr"