workflow/ci: Add checks:write permission and explicit reopened trigger

The CI action now creates individual GitHub Check Runs per test, which
requires 'checks: write' permission on the GITHUB_TOKEN. Also make the
pull_request trigger types explicit to include 'reopened', allowing CI
to be retriggered by closing and reopening a PR.

Author: Vudentz

.github/workflows/ci.yml

@@ -1,6 +1,12 @@
 name: CI
 
-on: [pull_request]
+on:
+  pull_request:
+    types: [opened, synchronize, reopened]
+
+permissions:
+  checks: write
+  pull-requests: write
 
 jobs:
   ci: