[buildkite] Pin version of bun being used due to bug in latest (1.0.5) (#100720) (#100722)

(cherry picked from commit 00c54ae)

Author: brianseeders

.buildkite/scripts/pull-request/pipeline.sh

@@ -3,7 +3,7 @@
 set -euo pipefail
 
 echo --- Installing bun
-npm install -g bun
+npm install -g bun@1.0.4
 
 echo --- Generating pipeline
 bun .buildkite/scripts/pull-request/pipeline.generate.ts