[browser][coreCLR] temporarily disabled System.Runtime.Tests

[pavelsavara]

This is quick and dirty disabling part of the System.Runtime.Tests to get us started with testing new platform. I didn't try to fix any of them for now.

[dotnet-policy-service]

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

[dotnet-policy-service]

Tagging subscribers to this area: @dotnet/interop-contrib
See info in area-owners.md if you want to be subscribed.

[lewing]

 [ActiveIssue("https://github.com/dotnet/runtime/issues/123011", typeof(PlatformDetection), nameof(PlatformDetection.IsBrowser), nameof(PlatformDetection.IsCoreCLR)]

Or IsCoreCLRInterpreter