NO-ISSUE fix: if expression

.gitea/workflows/pr-title-check.yaml

@@ -15,7 +15,7 @@ jobs:
         run: |
           title="${{ gitea.event.pull_request.title }}"
           echo "Checking PR title: $title"
-          if [[ ! "$title" =~ ^(BLOG-[0-9]+|NO-ISSUE) [A-Z].+$ ]]; then
+          if [[ ! "$title" =~ '^(BLOG-[0-9]+|NO-ISSUE) [A-Z].+$' ]]; then
             echo 'The title is not meet the format `BLOG-XXX Title title title`'
             exit 1
           else