HHH-15468 Set permissions

.github/workflows/contributor-build.yml

@@ -14,6 +14,8 @@ on:
     branches:
       - '6.0'
 
+permissions: {} # none
+
 # See https://github.com/hibernate/hibernate-orm/pull/4615 for a description of the behavior we're getting.
 concurrency:
   # Consider that two builds are in the same concurrency group (cannot run concurrently)
@@ -25,6 +27,8 @@ concurrency:
 
 jobs:
   build:
+    permissions:
+      contents: read
     name: Java 11
     runs-on: ubuntu-latest
     strategy: