[EngSys] Do not suppress typespec requirement check if typespec exists in spec repo

https://github.com/Azure/azure-rest-api-specs/pull/40408#discussion_r2985395781
There's a PR which adds a suppression to skip `TypeSpecRequirement` check
but this service has already completed the typespec migration: https://github.com/Azure/azure-rest-api-specs/tree/df35439f379a04fb0e47548336c093b3cdde2ca0/specification/search/resource-manager/Microsoft.Search/Search

I think typespec requirement suppression should not take effect when typespec exists in spec repo

cc @qiaozha

Start by reading the TypeSpecRequirement check and the suppression discussed in PR 40408, then compare it with the existing TypeSpec content under specification/search/resource-manager/Microsoft.Search/Search. Done means the suppression no longer skips the requirement check when TypeSpec exists in the spec repository.

Written by the indexing model from the issue text.