Update CHANGELOG.md for 11.7.0

[ci skip]

changelogs/unreleased/55883-modal-header-titles-have-an-unnecessary-top-margin.yml

----
-title: Remove top margin in modal header titles
-merge_request: 24108
-author:
-type: fixed

changelogs/unreleased/55945-suggested-change-highlight.yml

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-title: Add syntax highlighting to suggestion diff
-merge_request: 24156
-author:
-type: fixed

changelogs/unreleased/55958-inconsistent-spacing-between-note-and-user-avatar-in-discussions.yml

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-title: Fix spacing on discussions
-merge_request: !24197
-author:
-type: fixed

changelogs/unreleased/56076-releases-margin.yml

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-title: Fixes missing margin in releases block
-merge_request:
-author:
-type: fixed

changelogs/unreleased/ab-50763-persist-index.yml

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-title: Add indexes to speed up CI query.
-merge_request: 23188
-author:
-type: performance

changelogs/unreleased/ac-releases-api-with-assets.yml

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-title: Support CURD operation for Links as one of the Release assets
-merge_request: 24056
-author:
-type: changed

changelogs/unreleased/ac-releases-api.yml

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-title: Releases API
-merge_request: 23795
-author:
-type: added

changelogs/unreleased/ac-releases-name-sha-author.yml

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-title: Add name, author_id, and sha to releases table
-merge_request: 23763
-author:
-type: added

changelogs/unreleased/add-new-nginx-metrics.yml

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-title: Add NGINX 0.16.0 and above metrics
-merge_request: 22133
-author:
-type: added

changelogs/unreleased/allow-basic-auth-on-go-get-middleware.yml

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-title: Allow basic authentication on go get middleware
-merge_request: 23497
-author: Morty Choi @mortyccp
-type: changed

changelogs/unreleased/allow_collaboration_status_work.yml

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-title: Update a condition to visibility a merge request collaboration message
-merge_request: 23104
-author: Harry Kiselev
-type: other

changelogs/unreleased/blackst0ne-bump-rails-cve-2018-16476.yml

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-title: Bump Ruby on Rails to 5.0.7.1
-merge_request: 23396
-author: "@blackst0ne"
-type: security

changelogs/unreleased/blackst0ne-convert-specs-rails5-style.yml

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-title: "[Rails5.1] Update functional specs to use new keyword format"
-merge_request: 23095
-author: "@blackst0ne"
-type: other

changelogs/unreleased/blackst0ne-improve-encoding-helper-spec.yml

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-title: Update specs to exclude possible false positive pass
-merge_request: 23893
-author: "@blackst0ne"
-type: other

changelogs/unreleased/bvl-hide-confidential-events-take2.yml

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-title: Hide confidential events in the API
-merge_request: 23746
-author:
-type: other

changelogs/unreleased/ccr-49289_milestone_link.yml

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-title: Add project milestone link
-merge_request: 22552
-author:
-type: added

changelogs/unreleased/ci-dropdown-hidden-bug.yml

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-title: Don't hide CI dropdown behind diff summary
-merge_request:
-author: gfyoung
-type: fixed

changelogs/unreleased/depracated-migration-inheritance.yml

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-title: ActiveRecord::Migration -> ActiveRecord::Migration[5.0]
-merge_request: 23910
-author: Jasper Maes
-type: other

changelogs/unreleased/deprecated-actiondispatch-paramsparser.yml

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-title: Remove deprecated ActionDispatch::ParamsParser
-merge_request: 23848
-author: Jasper Maes
-type: other

changelogs/unreleased/deprecated-alias-method-chain.yml

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-title: 'Fix deprecation: alias_method_chain is deprecated. Please, use Module#prepend
-  instead'
-merge_request: 23887
-author: Jasper Maes
-type: other