Add script for triggering base AMI build

fmt

Author: scadu

.buildkite/scripts/trigger-base-rebuild.sh

@@ -0,0 +1,11 @@
+#!/bin/bash
+set -euo pipefail
+
+timestamp=$(date -u +"%Y-%m-%d %H:%M:%S UTC")
+
+echo "# Last updated: ${timestamp}" >"packer/windows/.trigger-base-build"
+echo "# Last updated: ${timestamp}" >"packer/linux/.trigger-base-build"
+
+git add packer/windows/.trigger-base-build packer/linux/.trigger-base-build
+
+echo "Base AMI rebuild triggers updated"