Use single quotes to avoid running commands

.github/workflows/ci.yml

@@ -299,10 +299,10 @@ jobs:
 
       - name: Check PR title length
         run: |
-          title="${{ github.event.pull_request.title }}"
+          title='${{ github.event.pull_request.title }}'
           title_length=${#title}
           if [ $title_length -gt 72 ]
           then
             echo "PR title is too long (greater than 72 characters)"
             exit 1
-          fi
+          fi