Add permissions to CI script (#58)

.github/workflows/test-package.yml

diff --git a/.github/workflows/test-package.yml b/.github/workflows/test-package.yml
index 6caf97c..72912f9 100644
--- a/.github/workflows/test-package.yml
+++ b/.github/workflows/test-package.yml
@@ -11,6 +11,7 @@
 
 env:
   PUB_ENVIRONMENT: bot.github
+permissions: read-all
 
 jobs:
   # Check code formatting and static analysis on a single OS (linux)