Add explicit permissions to workflows for security

Co-authored-by: andreasabel <1155218+andreasabel@users.noreply.github.com>

Author: Copilot

.github/workflows/example.yml

@@ -2,6 +2,9 @@ name: Example Usage
 
 on: [push, pull_request]
 
+permissions:
+  contents: read
+
 jobs:
   example:
     runs-on: ubuntu-latest

.github/workflows/test.yml

@@ -9,6 +9,9 @@ on:
   pull_request:
   workflow_dispatch:
 
+permissions:
+  contents: read
+
 jobs:
   test-linux:
     runs-on: ubuntu-latest