fix GITHUB_TOKEN permissions in workflows (#11392)

This pull request updates GitHub Actions workflow files to explicitly
set permissions for certain actions. (fixing the permissions issues)

**Workflow permissions updates:**

* Added explicit `issues: write` permission to the `assign.yml` workflow
to ensure it can modify issues as needed.
* Set `contents: write`, `actions: write`, and `checks: write`
permissions in the `build_all.yml` workflow to allow the workflow to
interact with repository contents, manage actions, and update checks.

.github/workflows/assign.yml

@@ -7,6 +7,9 @@ on:
     types: [created]
   workflow_dispatch:
 
+permissions:
+  issues: write
+
 jobs:
   assign:
     permissions: