[browser][sdk] WasmBuildIncrementalismTest.Build_IsIncremental

[pavelsavara]

Following files are modified on subsequent build, breaking incremental build

blazorwasm.runtimeconfig.json
RazorClassLibrary.staticwebassets.endpoints.json
blazorwasm.staticwebassets.endpoints.json

See
https://github.com/dotnet/sdk/blob/main/test/Microsoft.NET.Sdk.BlazorWebAssembly.Tests/WasmBuildIncrementalismTest.cs#L27

[dotnet-policy-service]

Tagging subscribers to 'arch-wasm': @lewing
See info in area-owners.md if you want to be subscribed.