Remove redundant config metadata

[pirj]

Previously, in rubocop-rspec, this was needed to have control over "config" shared context inclusion. We wanted to include ours, but not the one from rubocop.

Sibling to https://github.com/rubocop/rubocop-factory_bot/pull/21 and https://github.com/rubocop/rubocop-rspec/pull/1640

Thanks @r7kamura!

Replace this text with a summary of the changes in your PR. The more detailed you are, the better.

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Before submitting the PR make sure the following are checked:

• [x] Feature branch is up-to-date with main (if not - rebase it).
• [x] Squashed related commits together.
• [-] Added tests.
• [-] Updated documentation.
• [-] Added an entry to the CHANGELOG.md if the new code introduces user-observable changes.
• [x] The build (bundle exec rake) passes (be sure to run this locally, since it may produce updated documentation that you will need to commit).