add permissions block to autobuild-action.yml

Author: Stephan Brandauer

pr-checks/checks/autobuild-action.yml

@@ -1,6 +1,8 @@
 name: "autobuild-action"
 description: "Tests that the C# autobuild action works"
 versions: ["linked"]
+permissions:
+  contents: read
 steps:
   - uses: ./../action/init
     with: