Potential fix for code scanning alert no. 5: Workflow does not contain permissions (#2321)

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

Author: andyleejordan

.github/workflows/vim-test.yml

@@ -9,6 +9,9 @@ on:
   merge_group:
     types: [ checks_requested ]
 
+permissions:
+  contents: read
+
 jobs:
   vim:
     name: themis