add GH action permissions

Author: jenschude

.github/workflows/ci.yml

@@ -3,6 +3,8 @@ on:
 
 name: CI
 
+permissions: {}
+
 jobs:
   ci:
     name: Build and test

.github/workflows/release.yml

@@ -3,6 +3,10 @@ on:
 
 name: Release to Maven Central
 
+permissions:
+  contents: write
+  actions: write
+
 jobs:
   release:
     name: Build and release