.github(no-important-files-changed): add GitHub token

Previously, the workflow did not explicitly pass in the GitHub token,
which meant that commenting on PRs from forks wouldn't work. Fix that.

This commit reflects the upstream change [1].

[1] exercism/org-wide-files@bfc6fe525e05

.github/workflows/no-important-files-changed.yml

@@ -57,6 +57,7 @@ jobs:
         if: steps.check.outputs.important_files_changed == 'true'
         uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea
         with:
+          github-token: ${{ github.token }}
           script: |
             const body = "This PR touches files which potentially affect the outcome of the tests of an exercise. This will cause all students' solutions to affected exercises to be re-tested.\n\nIf this PR does **not** affect the result of the test (or, for example, adds an edge case that is not worth rerunning all tests for), **please add the following to the merge-commit message** which will stops student's tests from re-running. Please copy-paste to avoid typos.\n```\n[no important files changed]\n```\n\n For more information, refer to the [documentation](https://exercism.org/docs/building/tracks#h-avoiding-triggering-unnecessary-test-runs). If you are unsure whether to add the message or not, please ping `@exercism/maintainers-admin` in a comment. Thank you!"
             github.rest.issues.createComment({