[SDK generation pipeline] enable breaking change detector for SDK generated by codegen

For SDK generated by codegen, we hope to enable [breaking change detector](https://github.com/Azure/azure-sdk-for-python/tree/main/scripts/breaking_changes_checker) by default. So we need to add additional step in pipeline to add the package name in [RUN_BREAKING_CHANGES_PACKAGES](https://github.com/Azure/azure-sdk-for-python/blob/f2bc1fca2358eb5c07bf43eab64743bc3cdfc5cd/scripts/breaking_changes_checker/breaking_changes_allowlist.py#L10C1-L10C31)