Bump Testably.Abstractions.Testing from 4.3.6 to 4.3.8 - #257

Do not use Assert.Equal() to check for collection size. Use Assert.Single instead. (https://xunit.net/xunit.analyzers/rules/xUnit2013)

Do not use Assert.NotNull() on value type 'ReadOnlyFrugalList<T>'. Remove this assert. (https://xunit.net/xunit.analyzers/rules/xUnit2002)

Do not use Assert.Equal() to check for collection size. Use Assert.Empty instead. (https://xunit.net/xunit.analyzers/rules/xUnit2013)

Theory method 'From_IEnumerable' on test class 'IReadOnlyListTestSuite' does not use parameter '__'. Use the parameter, or remove the parameter and associated data. (https://xunit.net/xunit.analyzers/rules/xUnit1026)

Theory method 'From_IEnumerable' on test class 'IReadOnlyListTestSuite' does not use parameter '__'. Use the parameter, or remove the parameter and associated data. (https://xunit.net/xunit.analyzers/rules/xUnit1026)

The type 'T' cannot be used as type parameter 'TKey' in the generic type or method 'Dictionary<TKey, TValue>'. Nullability of type argument 'T' doesn't match 'notnull' constraint.

The type 'T' cannot be used as type parameter 'TKey' in the generic type or method 'Dictionary<TKey, TValue>'. Nullability of type argument 'T' doesn't match 'notnull' constraint.

Theory method 'From_IEnumerable' on test class 'IReadOnlyListTestSuite' does not use parameter '__'. Use the parameter, or remove the parameter and associated data. (https://xunit.net/xunit.analyzers/rules/xUnit1026)

The type 'T' cannot be used as type parameter 'TKey' in the generic type or method 'Dictionary<TKey, TValue>'. Nullability of type argument 'T' doesn't match 'notnull' constraint.

The type 'T' cannot be used as type parameter 'TKey' in the generic type or method 'Dictionary<TKey, TValue>'. Nullability of type argument 'T' doesn't match 'notnull' constraint.