[WF] Take back unneccessary permissions (#1492)

Co-authored-by: Benedikt Volkel <benedikt.volkel@cern.ch>

Author: benedikt-voelkel

.github/workflows/async-auto-label.yml

@@ -7,8 +7,7 @@ name: Apply requested async label
       - created
       - edited
 
-permissions:
-  pull-requests: write   # to update labels
+permissions: {}
 
 jobs:
   apply_async_labels:

.github/workflows/async-list-label.yml

@@ -9,8 +9,7 @@ name: Collect and print async labels
     branches:
       - master
 
-permissions:
-  pull-requests: write   # to update labels
+permissions: {}
 
 jobs:
   list_async_labels: