Merge branch '48661-node-6-and-7-compatibility-broken-by-recent-monaco-editor-upgrade' into 'master'

Resolve "Node 6 and 7 compatibility broken by recent Monaco editor upgrade"

Closes #48661

See merge request gitlab-org/gitlab-ce!20461

Add missing foreign key in import_export_uploads

See merge request gitlab-org/gitlab-ce!20458

Merge branch '48670-application-settings-may-not-be-invalidated-if-migrations-are-run' into 'master'

Resolve "Application settings may not be invalidated if migrations are run"

Closes #48670

See merge request gitlab-org/gitlab-ce!20389

Refactor rspec matchers in read_only_spec.rb

See merge request gitlab-org/gitlab-ce!20414

Redesign for mr widget info and pipelines section

Closes #46795

See merge request gitlab-org/gitlab-ce!20189

Resolve "GitLab Project export should use object storage"

Closes #46246

See merge request gitlab-org/gitlab-ce!20105

remove extra tick for eks docs

See merge request gitlab-org/gitlab-ce!20453

Use proper markdown rendering for previews

See merge request gitlab-org/gitlab-ce!19672

Add GPL Commitment language

See merge request gitlab-org/gitlab-ce!20449

Add ExclusiveLease guards for RepositoryCheck::{DispatchWorker,BatchWorker}

See merge request gitlab-org/gitlab-ce!20441

Make it clear that we need to enable omniauth for SAML and Bitbucket

See merge request gitlab-org/gitlab-ce!20421

CE: Move mailer preview to app directory

See merge request gitlab-org/gitlab-ce!20430

We saw in production that DispatchWorker was running about twice an hour,
which would schedule twice as many jobs as it should.

For some reason, BatchWorker was running 1000 times per hour, possibly
due to Sidekiq RSS kills that caused these jobs to restart.

Adding an ExclusiveLease prevents these jobs from running more
than they should.

Relates to https://gitlab.com/gitlab-com/infrastructure/issues/4526

Ability to check if underlying database is read only

See merge request gitlab-org/gitlab-ce!20345

Remove silly use of repo disk path

See merge request gitlab-org/gitlab-ce!20436

Add Repository#set_config and #delete_config

See merge request gitlab-org/gitlab-ce!20372

Add a new scenario to test GitHub import

Closes gitlab-qa#146

See merge request gitlab-org/gitlab-ce!19555

Delete deprecated object_storage_upload queue

See merge request gitlab-org/gitlab-ce!20371

Improves MR refactor getters and state and adds specs

Closes #48937

See merge request gitlab-org/gitlab-ce!20429

Update GitLab Pages to v1.0.0

See merge request gitlab-org/gitlab-ce!20404

(Part 2) Resolve "Recognise when a user is trying to validate a private SSH key"

Closes #46396

See merge request gitlab-org/gitlab-ce!19997

Revert "Merge branch 'rosulk-patch-12' into 'master'"

See merge request gitlab-org/gitlab-ce!20428

Resolve "Add dropdown to Groups link in top bar"

Closes #36234

See merge request gitlab-org/gitlab-ce!18280