Update CHANGELOG-EE.md for 13.12.0-ee

[ci skip]

ee/changelogs/unreleased/rspec-empty-lines-after-letitbe-ee-spec-features-issues.yml

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-title: Fix RSpec/EmptyLineAfterFinalLetItBe rubocop offenses in ee/spec/features/issues
-merge_request: 58396
-author: Abdul Wadood @abdulwd
-type: fixed

ee/changelogs/unreleased/rspec-empty-lines-after-letitbe-ee-spec-graphql-mutations.yml

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-title: Fix RSpec/EmptyLineAfterFinalLetItBe rubocop offenses in ee/spec/graphsql/mutations
-merge_request: 58390
-author: Abdul Wadood @abdulwd
-type: fixed

ee/changelogs/unreleased/rspec-empty-lines-after-letitbe-ee-spec-graphql-types.yml

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-title: Fix RSpec/EmptyLineAfterFinalLetItBe rubocop offenses in ee/spec/graphql/types
-merge_request: 58385
-author: Abdul Wadood @abdulwd
-type: fixed

ee/changelogs/unreleased/rspec-empty-lines-after-letitbe-ee-spec-helpers.yml

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-title: Fix RSpec/EmptyLineAfterFinalLetItBe rubocop offenses in ee/spec/helpers
-merge_request: 58383
-author: Abdul Wadood @abdulwd
-type: other

ee/changelogs/unreleased/rspec-empty-lines-after-letitbe-ee-spec-lib-gitlab-elastic.yml

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-title: Fix RSpec/EmptyLineAfterFinalLetItBe rubocop offenses in ee/spec/lib/gitlab/elastic
-merge_request: 58381
-author: Abdul Wadood @abdulwd
-type: fixed

ee/changelogs/unreleased/rspec-empty-lines-after-letitbe-ee-spec-projects.yml

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-title: Fix RSpec/EmptyLineAfterFinalLetItBe rubocop offenses in ee/spec/services/projects
-merge_request: 58330
-author: Abdul Wadood @abdulwd
-type: fixed

ee/changelogs/unreleased/rspec-empty-lines-after-letitbe-ee-spec-support.yml

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-title: Fix RSpec/EmptyLineAfterFinalLetItBe rubocop offenses in ee/spec/support
-merge_request: 58292
-author: Abdul Wadood @abdulwd
-type: fixed

ee/changelogs/unreleased/rspec-empty-lines-after-letitbe-ee-spec-todo-service.yml

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-title: Fix RSpec/EmptyLineAfterFinalLetItBe rubocop offenses in todo_service_spec.rb
-merge_request: 58310
-author: Abdul Wadood @abdulwd
-type: fixed

ee/changelogs/unreleased/sh-enable-load-balancing-atomic-replica-ff.yml

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-title: Switch load_balancing_atomic_replica feature flag on by default
-merge_request: 60574
-author:
-type: fixed

ee/changelogs/unreleased/sh-fix-external-validation-trial-status.yml

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-title: Return correct trial status in CI external pipeline validation
-merge_request: 61104
-author:
-type: fixed

ee/changelogs/unreleased/sh-require-credit-card-retry-build.yml

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-title: Check credit card requirement when retrying a CI build on GitLab.com
-merge_request: 62050
-author:
-type: fixed

ee/changelogs/unreleased/vij-add-membership-type-badges.yml

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-title: Add a new badge for billable membership types
-merge_request: 61366
-author:
-type: changed

ee/changelogs/unreleased/vij-add-removable-to-billable-member.yml

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-title: Expose whether a BillableMember is removable
-merge_request: 61566
-author:
-type: changed

ee/changelogs/unreleased/vij-billable-member-source.yml

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-title: Return billable member relationship to a group in REST API
-merge_request: 60600
-author:
-type: changed

ee/changelogs/unreleased/vij-delete-billable-error.yml

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-title: Return an appropriate error message when failing to remove billable members
-merge_request: 60404
-author:
-type: changed

ee/changelogs/unreleased/vij-prevent-invited-group-member-removal.yml

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-title: Add a new error modal for billable member removal
-merge_request: 61509
-author:
-type: changed

ee/changelogs/unreleased/vs-billable-members-list-drilldown.yml

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-title: Add tests for the details table
-merge_request: 59357
-author:
-type: added