Update CHANGELOG.md for 8.16.0

[ci skip]

changelogs/unreleased/badge-color-on-white-bg.yml

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-title: Added lighter count badge background-color for on white backgrounds
-merge_request: 7873
-author:

changelogs/unreleased/bug-project-feature-compatibility.yml

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-title: Mutate the attribute instead of issuing a write operation to the DB in `ProjectFeaturesCompatibility`
-  concern.
-merge_request: 8552
-author:

changelogs/unreleased/clipboard-button-text.yml

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-title: 'Copy <some text> to clipboard'
-merge_request: 8535

changelogs/unreleased/didemacet-ci-lint-page.yml

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-title: Change CI template linter textarea with Ace Editor
-merge_request: 8452
-author: Didem Acet

changelogs/unreleased/dot-in-project-queries.yml

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-title: Allow API query to find projects with dots in their name
-merge_request:
-author: Bruno Melli

changelogs/unreleased/dz-nested-group-misc.yml

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-title: Show nested groups tab on group page
-merge_request: 8308
-author:

changelogs/unreleased/dz-rename-invalid-users.yml

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-title: Rename users with namespace ending with .git
-merge_request: 8309
-author:

changelogs/unreleased/env-var-in-redis-config.yml

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-title: Allow to use ENV variables in redis config
-merge_request: 8073
-author: Semyon Pupkov

changelogs/unreleased/feature-1376-allow-write-access-deploy-keys.yml

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-title: Allow to add deploy keys with write-access
-merge_request: 5807
-author: Ali Ibrahim

changelogs/unreleased/feature-admin-merge-groups-and-projects.yml

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-title: Merged the 'Groups' and 'Projects' tabs when viewing user profiles
-merge_request: 8323
-author: James Gregory

changelogs/unreleased/feature-gitaly-feature-flag.yml

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-title: Pass Gitaly resource path to gitlab-workhorse if Gitaly is enabled
-merge_request: 8440
-author:

changelogs/unreleased/feature-log-ldap-to-application-log.yml

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-title: Log LDAP blocking/unblocking events to application log
-merge_request: 8042
-author: Markus Koller

changelogs/unreleased/feature-more-storage-statistics.yml

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-title: Add more storage statistics
-merge_request: 7754
-author: Markus Koller

changelogs/unreleased/filename-to-file-path.yml

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-title: Rename filename to file path in tooltip of file header in merge request diff
-merge_request: 8314
\ No newline at end of file

changelogs/unreleased/fill-authorized-projects.yml

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-title: Fill missing authorized projects rows
-merge_request:
-author:

changelogs/unreleased/fix-api-deprecation.yml

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-title: Fix a Grape deprecation, use `#request_method` instead of `#route_method`
-merge_request:
-author:

changelogs/unreleased/fix-blame-500.yml

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-title: Fix blame 500 error on invalid path.
-merge_request: 25761
-author: Jeff Stubler

changelogs/unreleased/fix-boards-search-typo.yml

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-title: 'Fix typo: seach to search'
-merge_request: 8370
-author:

changelogs/unreleased/fix-broken-url-on-group-avatar.yml

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-title: Fix broken url on group avatar
-merge_request: 8464
-author: hogewest

changelogs/unreleased/fix-build-sort-order.yml

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-title: Sort numbers in build names more intelligently
-merge_request: 8277
-author: