RoboCop: Fix spelling of cop departments

What does this MR do and why?

This MR fixes the following RuboCop warnings:

spec/lib/gitlab/audit/target_spec.rb: Rspec/VerifiedDoubles has the wrong namespace - should be RSpec
spec/models/concerns/database_event_tracking_spec.rb: Rspec/LeakyConstantDeclaration has the wrong namespace - should be RSpec
spec/models/concerns/database_event_tracking_spec.rb: Rspec/ExpectGitlabTracking has the wrong namespace - should be RSpec

Screenshots

Before ⚠	After ✅

How to set up and validate locally

$ bundle exec rubocop spec/lib/gitlab/audit/target_spec.rb spec/models/concerns/database_event_tracking_spec.rb

MR acceptance checklist

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• I have evaluated the MR acceptance checklist for this MR.