build: harden frontend-admin-tests.yml permissions

Signed-off-by: Alex <aleksandrosansan@gmail.com>

.github/workflows/frontend-admin-tests.yml

@@ -3,6 +3,9 @@ name: "Frontend admin tests powered by Sauce Labs"
 
 on: [push]
 
+permissions:
+  contents: read # to fetch code (actions/checkout)
+
 jobs:
   withplugins:
     name: with plugins

.github/workflows/frontend-tests.yml

@@ -3,6 +3,9 @@ name: "Frontend tests powered by Sauce Labs"
 
 on: [push]
 
+permissions:
+  contents: read # to fetch code (actions/checkout)
+
 jobs:
   withoutplugins:
     name: without plugins