[SDK automation] Logs filtered by `scriptWarning` should be shown in check page

## Context
Current SDK automation tool will show logs filtered by `scriptError` in [check page](https://github.com/Azure/azure-rest-api-specs/pull/33580/checks?check_run_id=39720801792). However, logs in `scriptError` will also signal the pipeline that the generation process failed.

There's situation where Java wants some messages to show up in check page but don't want the script to be considered failed. One such case is when the PR is migrating from Swagger to TypeSpec, and there are handwritten customization code, we'll clean up the customization code to avoid compilation failure. We want to let the user know about this.

## Proposal
We could leverage current `scriptWarning`, to filter necessary messages for check page. In the meanwhile, the script will not be considered failure compared to `scriptError`.

/cc @weidongxu-microsoft