[EG] remove media services -- is retired

[l0lawrence]

No description provided.

[openapi-pipeline-app]

Next Steps to Merge

Next steps that must be taken to merge this PR:

• ❌ This is the public specs repo main branch which is not intended for iterative development.
  You must acknowledge that you understand that after this PR is merged, you won't be able to stop your changes from being published to Azure customers.
  If this is what you intend, add PublishToCustomers label to your PR.
  Otherwise, retarget this PR onto a feature branch, i.e. with prefix release- (see aka.ms/azsdk/api-versions#release--branches).
• ❌ This PR has at least one breaking change (label: BreakingChangeReviewRequired).
  To unblock this PR, follow the process at aka.ms/brch.
• ❌ The required check named Swagger BreakingChange has failed. To unblock this PR, follow the process at aka.ms/brch.

[openapi-pipeline-app]

Generated ApiView

Language	Package Name	ApiView Link
.Net	Azure.Messaging.EventGrid.SystemEvents	https://apiview.dev/Assemblies/Review/3e102a891e5445af8be8cde833dbb702?revisionId=e985677ba265499a9bfed47a4248e946
Python	azure-eventgrid	https://apiview.dev/Assemblies/Review/c554ddbabc6e40348998b1656e0ff585?revisionId=0d65259c3e6a4ba5a83cffb19910ffc1
TypeSpec	Azure.Messaging.EventGrid.SystemEvents	https://apiview.dev/Assemblies/Review/bf48b2982ff74cd796f5900a221af2d5?revisionId=be508eefa137472a942ee5bfd7ab8b08

[azure-sdk]

API change check

APIView has identified API level changes in this PR and created following API reviews.

Microsoft.ApiCenter