Potential fix for code scanning alert no. 15: Workflow does not contain permissions (#249)

Co-authored-by: Copilot Autofix powered by AI <62310815+github-advanced-security[bot]@users.noreply.github.com>

Author: arunim2405

.github/workflows/build_test.yml

@@ -4,6 +4,9 @@ on:
   push:
   pull_request:
 
+permissions:
+  contents: read
+
 jobs:
   run_test:
     runs-on: ubuntu-latest