Update .github/workflows/reusable-regenerate-readme.yml

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: swissspidy

.github/workflows/reusable-regenerate-readme.yml

@@ -91,8 +91,7 @@ jobs:
 
           ROOTS=$(echo "$DOCUMENTED" | awk '{print $1}' | sort -u)
 
-          DUMP=$(wp cli cmd-dump)
-          if [ -z "$DUMP" ]; then
+          if ! DUMP=$(wp cli cmd-dump); then
             echo "::error::Failed to dump commands"
             exit 1
           fi