[wasm] Re-enable several test suites

[mdh1418]

This PR looks to re-enable the following test suites for WebAssembly now that they pass/skip:

• System.Threading.Tasks [wasm] Disable problematic threading tests in System.Threading.Tasks.Tests #38355
• System.Threading.Channels Tested locally
• Microsoft.Extensions.FileProviders.Physical [Wasm] Skip Microsoft.Extensions.FileProviders.Physical tests #38396

[ghost]

Tagging subscribers to this area: @safern, @ViktorHofer
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[safern]

System.TypeInitializationException : The type initializer for 'System.Runtime.Serialization.Formatters.Binary.Converter' threw an exception.\n---- System.IO.FileNotFoundException :

There is one test failure in System.Threading.Channels.Tests.

I'm taking a look at those kind of failures which are impacting like 200 tests.

[steveisok]

@safern, @akoeplinger thinks it might be mscorlib being excluded in the WasmAppBuilder.

[safern]

Yes that seems the most likely reason.

[akoeplinger]

@mdh1418 can you please open an issue for the System.Runtime.Serialization.Formatters.Binary.Converter so we can disable it with an ActiveIssue for now in this PR?

[safern]

We can disable against: #37648 -- I'm using that to fix those remainders of FileNotFoundException.

[mdh1418]

The issue for System.Runtime.Serialization.Formatters.Binary.Converter is here #38443

[safern]

@mdh1418 let's please disable against the issue I posted above and close the other issue, since this failure is happening in all tests that use serialization, not just in this one.