chore: replace tj-actions/changed-files github action (#33791)

### Issue # (if applicable)

Closes #<issue number here>.

### Reason for this change
replace tj-actions/changed-files github action with the step-security/changed-files action as recommended in this issue
https://www.stepsecurity.io/blog/harden-runner-detection-tj-actions-changed-files-action-is-compromised

### Checklist
- [X] My code adheres to the [CONTRIBUTING GUIDE](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md) and [DESIGN GUIDELINES](https://github.com/aws/aws-cdk/blob/main/docs/DESIGN_GUIDELINES.md)

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

Author: moelasmar

.github/workflows/request-cli-integ-test.yml

@@ -19,7 +19,7 @@ jobs:
           persist-credentials: false
       - name: Find changed cli files
         id: changed-cli-files
-        uses: tj-actions/changed-files@dcc7a0cba800f454d79fff4b993e8c3555bcc0a8
+        uses: step-security/changed-files@3dbe17c78367e7d60f00d78ae6781a35be47b4a1
         with:
           base_sha: ${{ github.event.pull_request.base.sha }}
           files_yaml: |