Update CHANGELOG.md for 10.8.0

CHANGELOG.md

changelogs/unreleased/10244-add-project-ci-cd-settings.yml

changelogs/unreleased/16957-issue-due-email.yml

changelogs/unreleased/21677-run-pipeline-word.yml

changelogs/unreleased/25010-collapsed-sidebar-tooltips.yml

.../30739-fix-joined-information-on-project-members-page.yml

...nreleased/32617-fix-template-selector-menu-visibility.yml

changelogs/unreleased/33697-pipelines-json-endpoint.yml

changelogs/unreleased/33697-remove-ujs-action-big-graph.yml

...ogs/unreleased/34262-show-current-labels-when-editing.yml

...ed/36762-reconcile-project-templates-with-auto-devops.yml

changelogs/unreleased/36983-osw-heading-labels-color-fix.yml

...sed/40402-time-estimate-system-notes-can-be-confusing.yml

changelogs/unreleased/40487-axios-pipelines.yml

...leased/41059-calculate-artifact-size-more-efficiently.yml

...d/41082-make-deploykeys-table-more-clearly-structured.yml

...logs/unreleased/41748-vertical-misalignment-login-box.yml

...81-allow-group-owner-to-enable-runners-from-subgroups.yml

...nreleased/42099-port-push-mirroring-to-ce-ce-port-v-2.yml

...ed/42543-hide-divergence-graph-on-branches-for-mobile.yml