Update CHANGELOG-EE.md for 13.9.0-ee

[ci skip]

ee/changelogs/unreleased/296648-confidential-issue.yml

----
-title: Resolve Filter count does not get reflected in Test Cases
-merge_request: 52889
-author:
-type: fixed

ee/changelogs/unreleased/296669-ui-support-customizable-timeouts-for-git-cli-2fa.yml

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-title: Support setting customizable timeouts for git CLI 2FA via UI & API
-merge_request: 52769
-author:
-type: added

ee/changelogs/unreleased/296717-threat-monitoring-alerts-details.yml

----
-title: Add route for threat monitoring alert details
-merge_request: 51417
-author:
-type: added

ee/changelogs/unreleased/296776-issues-created-from-vulnerabilities-set-to-confidential-by-defa.yml

----
-title: Issues created from Vulnerabilities set to Confidential by default
-merge_request: 52127
-author:
-type: changed

ee/changelogs/unreleased/296833_consider_context_path_in_jira_issue_entity.yml

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-title: Fix Jira issue list links when Jira runs on a subpath
-merge_request: 51797
-author:
-type: fixed

ee/changelogs/unreleased/298783-log-user-instance-request-in-audit-events-2.yml

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-title: Log user instance request and rejection in Audit Events
-merge_request: 52543
-author:
-type: added

ee/changelogs/unreleased/298840-ajk-fix-epic-id-processing.yml

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-title: Fix epic assignment in the createIssue mutation
-merge_request: 51817
-author:
-type: fixed

ee/changelogs/unreleased/298919-fix-response-fields-for-vulns.yml

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-title: Fix Vuln detail and modal when reasonPhrase is empty string
-merge_request: 52156
-author:
-type: fixed

ee/changelogs/unreleased/299065-fj-add-group-repository-storage-move-api-endpoints.yml

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-title: Add group repository storage move endpoints
-merge_request: 53016
-author:
-type: added

ee/changelogs/unreleased/299099-update-es-counts-query.yml

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-title: Improve Advanced Search counts queries
-merge_request: 51971
-author:
-type: performance

ee/changelogs/unreleased/299179-edit-permission-not-possibe-in-subgroup-of-group-with-ldap-sync.yml

----
-title: Remove LDAP "Edit Permissions" button for inherited group members
-merge_request: 52847
-author:
-type: fixed

ee/changelogs/unreleased/299209-doc-updates-for-jira-issue-creation-configuration-for-vulnerabi.yml

----
-title: Ability to create a Jira issue for a vulnerability
-merge_request: 54182
-author:
-type: added

ee/changelogs/unreleased/299247-second-iteration-of-exporting-requirements.yml

----
-title: Modify herders in exported requirements CSV file
-merge_request: 52118
-author:
-type: changed

ee/changelogs/unreleased/299347-enable-optimized_merge_request_count_with_merged_at_filter-ff.yml

----
-title: Improve the performance of the Merge Request Analytics chart
-merge_request: 53704
-author:
-type: performance

ee/changelogs/unreleased/299462-create-issue-from-vulnerability-details-edited-text-is-discarde.yml

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-title: Fixed bug that overwrote issue description changes from vulnerabilities
-merge_request: 52376
-author:
-type: fixed

ee/changelogs/unreleased/299504-epic-swimlanes-negated-filters-not-filtering.yml

----
-title: Swimlanes - Support negated filters
-merge_request: 52449
-author:
-type: fixed

ee/changelogs/unreleased/299590-experiment-cleanup-update-issue-weights-paywall-ctas.yml

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-title: Update Issue Weights Paywall CTAs
-merge_request: 53117
-author:
-type: changed

ee/changelogs/unreleased/299861-compliance-framework-permissions-change.yml

----
-title: Disable ability for maintainers to change project compliance framework
-merge_request: 53370
-author:
-type: changed

ee/changelogs/unreleased/299941-threat-monitoring-alerts-UI-docs.yml

----
-title: Enable threat_monitoring_alerts feature flag by default
-merge_request: 53776
-author:
-type: added

ee/changelogs/unreleased/299943-follow-up-from-project-access-token-api.yml

----
-title: Log token_id in project access token audit events instead of user_id
-merge_request: 52535
-author:
-type: changed