[Fix #5022] Fix false negative for Lint/DuplicateMethods inside class << self

[dvandersluis]

Requires rubocop/rubocop-ast#197 in order to fix Node#parent_module_name.

Properly handles the updated format of parent_module_name and adds tests to ensure the case from #5022 works.

Also reverts the pending tests in #9995.

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