Add log_error() to Docker inline script for DEB packaging

- Fix 'log_error: command not found' in DEB packaging stage
- Docker run uses inline bash script with separate function definitions
- Added log_error() after log_info() in Docker inline script (line 712)
- Function executes inside container context where DEB packaging runs

qt6-after/qt6-migrated-legatus/new_docker_build_release2.sh

@@ -709,6 +709,10 @@ log_info() {
   echo "[INFO] $*"
 }
 
+log_error() {
+  printf 'ERROR: %s\n' "$*" >&2
+}
+
 die() {
   echo "[ERROR] $*" >&2
   exit 1