Breaking change false positive when changing readonly property from true to false...

I changed few properties readonly from true to false and breaking change tool flagging those. But, I don't expect those to be breaking , it is same as adding new property ( not removing it which is changing readonly from false to true).

PR: https://github.com/Azure/azure-rest-api-specs-pr/pull/1605

The issue names no source files or tests; begin at the command-line breaking-change comparison for OpenAPI specs and reproduce a readonly true-to-false change. Done means the tool no longer flags that transition as breaking while preserving the false-to-true behavior, with the reported Azure REST API Specs case covered by verification.

索引モデルが issue の本文から書いたものです。