ci: drop privileges to contents: read (#155)

Drop the `ci.yml` privileges to `contents: read` following the principle of the least privilege.

Co-authored-by: Simone Basso <bassosimone@gmail.com>

Author: abhi-14gyan

.github/workflows/ci.yml

@@ -7,6 +7,9 @@ on:
   pull_request:
     branches: [ main ]
 
+permissions:
+  contents: read
+
 jobs:
   test-quality:
     name: Code Quality Checks