chore: fix yarn upgrade workflow (#33533)

### Reason for this change

Fix failed workflow yarn upgrade https://github.com/aws/aws-cdk/actions/runs/13445238910/job/37568949091

Since CLI is moved out, there is no `packages/aws-cdk` dir.

Author: GavinZZ

.github/workflows/yarn-upgrade.yml

@@ -77,8 +77,6 @@ jobs:
       - name: Run "yarn upgrade"
         run: yarn upgrade
 
-      - name: Regenerate CLI attributions
-        run: cd packages/aws-cdk && yarn pkglint
       - name: Regenerate Integ Runner attributions
         run: cd packages/@aws-cdk/integ-runner && yarn pkglint