fix: Remove redundant context declaration in github action script

This change removes the redundant `const { context } = require('@actions/github');` line from the github action script. The `context` object is globally available in the script's environment, so this declaration was unnecessary and caused a `SyntaxError`.

Author: google-labs-jules[bot]

.github/workflows/pr_assignee_check.yml

@@ -11,7 +11,6 @@ jobs:
       - uses: actions/github-script@v6
         with:
           script: |
-            const { context } = require('@actions/github');
             const assignees = context.payload.pull_request.assignees;
             if (assignees.length === 0) {
               core.setFailed('No one is assigned to this pull request.');