fix(workflows): elevate GITHUB_TOKEN permissions when needed (#822)

I am not 100% sure I was able to fix all the cases in which we
need higher permissions than the strict default.

At least, I tried.

It may be reasonable to make an interim release to check whether I
successfully fixed all the cases.

Ref issue: https://github.com/ooni/probe/issues/2154

.github/workflows/qafbmessenger.yml

@@ -1,9 +1,10 @@
-# qafbmessenger runs QA checks for the fbmessenger experiment
+# Runs QA checks for the fbmessenger experiment
 name: "qafbmessenger"
 on:
   push:
     branches:
       - "release/**"
+
 jobs:
   test:
     runs-on: ubuntu-20.04