fix "Fixup blank lockfiles"

Author: gilesknap

.github/workflows/code.yml

@@ -173,7 +173,7 @@ jobs:
 
       - name: Fixup blank lockfiles
         # Github release artifacts can't be blank
-        run: for f in lockfiles/*; [ -s $f ] || echo '# No requirements' >> $f; done
+        run: for f in lockfiles/*; do [ -s $f ] || echo '# No requirements' >> $f; done
 
       - name: Github Release
         # We pin to the SHA, not the tag, for security reasons.