Potential fix for code scanning alert no. 37: Workflow does not contain permissions

Co-authored-by: Copilot Autofix powered by AI <62310815+github-advanced-security[bot]@users.noreply.github.com>

Author: JoernBerkefeld

.github/workflows/close_issues_on_merge.yml

@@ -9,6 +9,10 @@ on:
 
 jobs:
   closeIssueOnPrMergeTrigger:
+    permissions:
+      contents: read
+      pull-requests: read
+      issues: write
 
     runs-on: ubuntu-latest