Remove invalid ms.subservice (#49494)

Author: gewarren

docfx.json

@@ -595,7 +595,6 @@
                 "docs/framework/data/wcf/**/**.md": "wcf",
                 "docs/framework/docker/**/**.md": "dotnet-docker",
                 "docs/framework/install/**/**.md": "install-deployment",
-                "docs/framework/migration-guide/**/**.md": "app-compat",
                 "docs/framework/network-programming/**/**.md": "networking",
                 "docs/framework/wcf/**/**.md": "wcf",
                 "docs/framework/windows-workflow-foundation/**/**.md": "wf",