Missing SetTestClassParallelize in XunitTestGeneratorProvider

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As per the latest update,
https://github.com/techtalk/SpecFlow/commits/master/TechTalk.SpecFlow.Generator/UnitTestProvider/IUnitTestGeneratorProvider.cs got a new method called SetTestClassParallelize. Need to implement this method in XUnitTestGeneratorProvider.cs inside XunitRetry.Generator.SpecflowPlugin.

Otherwise, it's throwing an error reading SetTestClassParallelize is not implemented whenever I tried to use retry attribute in my Specflow feature file.

I have created a branch where I have implemented the method as below:

public void SetTestClassParallelize(TestClassGenerationContext generationContext)
        {
            //doing nothing
        }

PR created here: #5