Update GitHub Actions workflow to enhance permissions and SDK reference

- Added `sdkRef` parameter to specify the SDK version.
- Updated job permissions to allow read access to contents and write access for checks and pull requests.
- Configured secrets to inherit from the repository.

Author: andy1li

.github/workflows/test.yml

@@ -12,3 +12,10 @@ concurrency:
 jobs:
   test_course_definition:
     uses: codecrafters-io/course-sdk/.github/workflows/test-course-definition.yml@main
+    with:
+      sdkRef: main
+    permissions:
+      contents: read
+      checks: write
+      pull-requests: write
+    secrets: inherit