Update github-actions-demo.yml

fix typo
$TARGET_FOLDER -> "$TARGET_FOLDER"

Author: PapyrusNotes

.github/workflows/github-actions-demo.yml

@@ -27,5 +27,5 @@ jobs:
         run: |
           TARGET_FOLDER = "${{ github.workspace }}/DescriptiveStatistics"
           echo "Listing all files in $TARGET_FOLDER of the workspace directory "
-          find $TARGET_FOLDER -mindepth 2 -type f -name "*.py"
+          find "$TARGET_FOLDER" -mindepth 2 -type f -name "*.py"
       - run: echo "🍏 This job's status is ${{ job.status }}."