Update version of NUnit related packages (#12639)
Update version of NUnit related packages (#12639)

I hitting bunch of exceptions during execution of `dotnet test tests/FSharp.Compiler.Service.Tests/FSharp.Compiler.Service.Tests.fsproj` on Linux with only .NET 6 installed.
```
System.ArgumentException: Unknown framework version 6.5 (Parameter 'version')
   at NUnit.Framework.Internal.RuntimeFramework.ThrowInvalidFrameworkVersion(Version version)
   at NUnit.Framework.Internal.RuntimeFramework.InitFromFrameworkVersion(Version version)
   at NUnit.Framework.Internal.RuntimeFramework..ctor(RuntimeType runtime, Version version)
   at NUnit.Framework.Internal.RuntimeFramework.<>c.<.cctor>b__33_0()
   at System.Lazy`1.ViaFactory(LazyThreadSafetyMode mode)
   at System.Lazy`1.ExecutionAndPublication(LazyHelper executionAndPublication, Boolean useDefaultConstructor)
   at System.Lazy`1.CreateValue()
   at System.Lazy`1.get_Value()
   at NUnit.Framework.Internal.RuntimeFramework.get_CurrentFramework()
   at NUnit.Framework.Internal.PlatformHelper..ctor()
   at NUnit.Framework.TestCaseAttribute.BuildFrom(IMethodInfo method, Test suite)+MoveNext()
   at NUnit.Framework.Internal.Builders.DefaultTestCaseBuilder.BuildFrom(IMethodInfo method, Test parentSuite)
   at NUnit.Framework.Internal.Builders.NUnitTestFixtureBuilder.AddTestCasesToFixture(TestFixture fixture, IPreFilter filter)
   at NUnit.Framework.Internal.Builders.NUnitTestFixtureBuilder.BuildFrom(ITypeInfo typeInfo, IPreFilter filter)
   at NUnit.Framework.Internal.Builders.DefaultSuiteBuilder.BuildFrom(ITypeInfo typeInfo, IPreFilter filter)
```

In spirit of https://github.com/dotnet/fsharp/issues/9947 maybe would be better to migrate these tests to XUnit
dsyme/fsharp,dsyme/fsharp,dsyme/fsharp,dsyme/fsharp,dsyme/fsharp,dsyme/fsharp,dsyme/fsharp