Fix undefined $repo variable in cleanup-multidevs

The script referenced $repo but the workflow sets GH_REPO. This caused
gh pr view to misparse arguments, concatenating PR numbers and failing.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: kurowski

local/etc/uceap.d/cleanup-multidevs.sh

@@ -3,7 +3,7 @@ function cleanup_multidevs() {
 	multidevs=($(terminus env:list $TERMINUS_SITE --field=id | grep -E '^pr-[0-9]+(-e2e)?$'))
 	for multidev in "${multidevs[@]}"; do
 		pr_id=$(echo "$multidev" | grep -oE '[0-9]+')
-		state=$(gh pr view "$pr_id" --repo "$repo" --json state -q ".state")
+		state=$(gh pr view "$pr_id" --repo "$GH_REPO" --json state -q ".state")
 		if [[ "$state" != "OPEN" ]]; then
 			echo "PR #$pr_id ($multidev) is $state"
 			terminus env:delete "$TERMINUS_SITE.$multidev" --yes