Re-enable SOS tests on Windows x86 when dotnet/runtime#129456 is resolved

[hoyosjs]

Several SOS tests are temporarily disabled on Windows x86 due to a regression in .NET 11 (dotnet/runtime#129456). The following tests are affected:

• SOSStackAndOtherTests.StackAndOtherTests
• SOSGCTests.GCTests
• SOSGCTests.GCPOHTests
• SOSMethodTests.VarargPInvokeInteropMD
• SOSStackTraceTests.StackTests

When dotnet/runtime#129456 is fixed, the SOSTestHelpers.SkipIfWinX86 guards added to those tests should be removed.

Tracking PR: #5874