Fix autocorrection error with nested offenses for Rails/IndexWith

[lovro-bikic]

Currently, code that registers nested offenses for Rails/IndexWith:

x.each_with_object({}) do |el, h|
# ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Prefer `index_with` over `each_with_object`.
  h[el] = el.each_with_object({}) do |inner_el, inner_h|
#         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Prefer `index_with` over `each_with_object`.
    inner_h[inner_el] = foo(inner_el)
  end
end

will fail on autocorrection with Parser::ClobberingError: Parser::Source::TreeRewriter detected clobbering error.

This PR fixes autocorrection by ignoring the node after first autocorrection, so the correction is done in multiple passes.

Since this cop shares logic with Rails/IndexBy, technically that cop is affected as well by this change.

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Before submitting the PR make sure the following are checked:

• The PR relates to only one subject with a clear title and description in grammatically correct, complete sentences.
• Wrote good commit messages.
• Commit message starts with [Fix #issue-number] (if the related issue exists).
• Feature branch is up-to-date with master (if not - rebase it).
• Squashed related commits together.
• Added tests.
• Ran bundle exec rake default. It executes all tests and runs RuboCop on its own code.
• Added an entry (file) to the changelog folder named {change_type}_{change_description}.md if the new code introduces user-observable changes. See changelog entry format for details.
• If this is a new cop, consider making a corresponding update to the Rails Style Guide.

[koic]

Thanks!