fix: define workflow permissions

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

Author: amatsagu

.github/workflows/go.yml

@@ -3,6 +3,9 @@
 
 name: Go
 
+permissions:
+  contents: read
+
 on:
   push:
     branches: [ "master" ]