Prepare for 2.0.7

[RobertoPrevato]

• Add the possibility to specify the ActivationScope class when instantiating
  the Container or the Services object. This class will be used when
  creating scopes. For the issue bug: opening a scope within a scope hides the original scope #55.
• Add an experimental class, TrackingActivationScope to support nested
  scopes transparently, using contextvars.ContextVar. For more context, see
  the tests test_nested_scope_1, test_nested_scope_2,
  test_nested_scope_async_1. For the issue bug: opening a scope within a scope hides the original scope #55.
• Raise a TypeError if trying to obtain a service from a disposed scope.
• Remove Python 3.8 from the build matrix, add Python 3.13.
• Handle setuptools warning: SetuptoolsDeprecationWarning: License classifiers are deprecated.