[Rule 1048] Missing rule for x-ms-enum, AddedXmsEnum

[Rick Winter]

The tool references rule 1048 which does not exist.
https://github.com/Azure/openapi-diff/tree/master/docs/rules/1048.md

[Jianye Xi]

Thanks for feedback, it's actually in https://github.com/Azure/openapi-diff/tree/main/docs/rules/1048.md, will fix the pipeline issue