Fix MSTEST0012/MSTEST0013 documentation about test class being static (#44431)

Author: Youssef1313

docs/core/testing/mstest-analyzers/mstest0012.md

@@ -32,20 +32,19 @@ A method marked with `[AssemblyInitialize]` should have valid layout.
 
 Methods marked with `[AssemblyInitialize]` should follow the following layout to be valid:
 
-- it can't be declared on a generic class
 - it should be `public`
 - it should be `static`
 - it should not be `async void`
 - it should not be a special method (finalizer, operator...).
 - it should not be generic
+- it should not be abstract
 - it should take one parameter of type `TestContext`
 - return type should be `void`, `Task` or `ValueTask`
 
 The type declaring these methods should also respect the following rules:
 
 - The type should be a class.
 - The class should be public or internal (if the test project is using the [DiscoverInternals] attribute).
-- The class shouldn't be static.
 - The class should be marked with [TestClass] (or a derived attribute)
 - the class should not be generic
 

docs/core/testing/mstest-analyzers/mstest0013.md

@@ -32,20 +32,19 @@ A method marked with `[AssemblyCleanup]` should have valid layout.
 
 Methods marked with `[AssemblyCleanup]` should follow the following layout to be valid:
 
-- it can't be declared on a generic class
 - it should be `public`
 - it should be `static`
 - it should not be `async void`
 - it should not be a special method (finalizer, operator...).
 - it should not be generic
+- it should not be abstract
 - it should not take any parameter, or starting with MSTest 3.8, it can have a single `TestContext` parameter
 - return type should be `void`, `Task` or `ValueTask`
 
 The type declaring these methods should also respect the following rules:
 
 - The type should be a class.
 - The class should be public or internal (if the test project is using the [DiscoverInternals] attribute).
-- The class shouldn't be static.
 - The class should be marked with [TestClass] (or a derived attribute)
 - the class should not be generic