tweak dir perms script

Author: hjwp

.github/workflows/tests.yml

@@ -32,7 +32,7 @@ jobs:
           docker run --rm \
             --mount type=bind,source=./,target=/app \
             -t hjwp/obeythetestinggoat-book-tester:latest \
-            bash -c "ls -d source/*/superlists/ | xargs -n1 git config --global --add safe.directory"
+            bash -c 'ls -d "$PWD/source/*/superlists/" | xargs -n1 git config --global --add safe.directory'
 
       - name: test chapter 1
         run: |