fix spacing of bash scripts

build-support/scripts/gen-changelog.sh

@@ -6,6 +6,11 @@ set -eo pipefail
 
 pr_number=$(gh pr list -H "$(git rev-parse --abbrev-ref HEAD)" -q ".[0].number" --json "number")
 
+if [ -z "$pr_number" ]; then
+  echo "Error: Could not find PR number."
+  exit 1
+fi
+
 # check if this changelog is referencing an enterprise change
 curdir=$(pwd)