Fix security issue: Add explicit permissions to coverage workflow

Co-authored-by: huangyiirene <7665279+huangyiirene@users.noreply.github.com>

Author: Copilot

.github/workflows/coverage.yml

@@ -6,6 +6,10 @@ on:
   pull_request:
     branches: [ "main" ]
 
+permissions:
+  contents: read
+  pull-requests: write
+
 jobs:
   coverage:
     name: Test Coverage Report