update to explicitly set shutdown hook

.github/workflows/build_and_test.yml

@@ -858,7 +858,7 @@ jobs:
       - name: Downloading vm-builder
         run: |
           # TEMPORARY: Pull custom version of vm-builder built from neondatabase/autoscaling#600.
-          curl -fL https://sharnoff.io/misc/8706cca48732d4f9/vm-builder-9d18874 -o vm-builder
+          curl -fL https://sharnoff.io/misc/8706cca48732d4f9/vm-builder-29ef2a1 -o vm-builder
           chmod +x vm-builder
 
       # Note: we need a separate pull step here because otherwise vm-builder will try to pull, and

vm-image-spec.yaml

@@ -13,6 +13,8 @@ commands:
     user: nobody
     sysvInitAction: respawn
     shell: 'DATA_SOURCE_NAME="user=cloud_admin sslmode=disable dbname=postgres" /bin/postgres_exporter'
+shutdownHook: |
+  su -p postgres --session-command '/usr/local/bin/pg_ctl stop -D /var/db/postgres/compute/pgdata -m fast --wait -t 10'
 files:
   - filename: pgbouncer.ini
     content: |