CI: Declare minimal set of permissions

Author: Turbo87

.github/workflows/ci.yml

@@ -8,6 +8,8 @@ on:
 
   pull_request:
 
+permissions: {}
+
 concurrency:
   group: ci-${{ github.head_ref || github.ref }}
   cancel-in-progress: true

.github/workflows/smoke-test.yml

@@ -3,6 +3,8 @@ name: Smoke Test
 on:
   workflow_dispatch:
 
+permissions: {}
+
 concurrency:
   group: smoke-test
   cancel-in-progress: true