chore: lock conversations on closed issues and PRs with message (#30941)

### Issue # (if applicable)


### Reason for this change

Lock conversations on closed issues and PRs to make sure important comments are not left on closed items and no one would be able to see it. Force people to create new issues instead.

### Description of changes

Lock conversations.

### Description of how you validated changes

Tested in a forked repo and it works correctly.

### Checklist
- [ ] 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: GavinZZ

.github/workflows/closed-issue-message.yml

@@ -0,0 +1,47 @@
+name: Lock Closed Issues and PRs with message
+
+on:
+  pull_request_target:
+    types: [closed]
+  issues:
+    types: [closed]
+
+jobs:
+  auto_comment:
+    permissions:
+      pull-requests: write
+      issues: write
+    runs-on: ubuntu-latest
+    steps:
+      - uses: aws-actions/closed-issue-message@v1
+        with:
+          repo-token: "${{ secrets.GITHUB_TOKEN }}"
+          message: |
+            Comments on closed issues and PRs are hard for our team to see. 
+            If you need help, please open a new issue that references this one.
+            If you wish to keep having a conversation with other community members under this issue feel free to do so.
+  lock:
+    permissions:
+      pull-requests: write
+      issues: write
+    runs-on: ubuntu-latest
+    needs: auto_comment
+    steps:
+      - name: Lock closed issue or PR
+        run: |
+          if [ "${{ github.event_name }}" == "issues" ]; then
+            ISSUE_NUMBER=${{ github.event.issue.number }}
+            ISSUE_URL=https://api.github.com/repos/${{ github.repository }}/issues/${ISSUE_NUMBER}/lock
+          else
+            ISSUE_NUMBER=${{ github.event.pull_request.number }}
+            ISSUE_URL=https://api.github.com/repos/${{ github.repository }}/issues/${ISSUE_NUMBER}/lock
+          fi
+
+          curl -s -X PUT -H "Authorization: token ${{ secrets.GITHUB_TOKEN }}" \
+          -H "Accept: application/vnd.github.v3+json" \
+          ${ISSUE_URL} \
+          -d @- <<EOF
+          {
+            "lock_reason": "resolved"
+          }
+          EOF