Update Contribution guidelines via new community contribution flow

See merge request gitlab-org/gitlab-ce!21761

Resolve "Add runner JSON schema"

Closes #51093

See merge request gitlab-org/gitlab-ce!21525

Backport EE changes (missing exports)

See merge request gitlab-org/gitlab-ce!21772

Backport EE changes to `app/assets/javascripts/filtered_search/issuable_filtered_search_token_keys.js`

Include correct CSS file for xterm in environments page

Closes #50956

See merge request gitlab-org/gitlab-ce!21768

Fix double title in merge request chat messages

Closes #44586

See merge request gitlab-org/gitlab-ce!21670

When the xterm dependency was moved to a npm dependency
the CSS file path was not updated correctly in the environments page.

In order for xterm to render properly, it needs the correct CSS path.

Merge branch '50944-unable-to-import-repository-undefined-method-import_file-for-nil-nilclass' into 'master'

Resolve "Unable to import repository:  undefined method `import_file' for nil:NilClass"

Closes #50944

See merge request gitlab-org/gitlab-ce!21765

Fix grammar (setup to set-up) in code comments, spec, views, etc.

See merge request gitlab-org/gitlab-ce!21699

closes https://gitlab.com/gitlab-org/gitlab-ce/issues/51093

Add retried jobs to pipeline stages

Closes #50461

See merge request gitlab-org/gitlab-ce!21558

Resolve "Send deployment information in job API"

Closes #50460

See merge request gitlab-org/gitlab-ce!21307

Support Kubernetes RBAC for GitLab Managed Apps for creating new clusters

Closes #29398

See merge request gitlab-org/gitlab-ce!21401

Fixed MR widget unresolved discussions state

See merge request gitlab-org/gitlab-ce!21705

Disable autocomplete for issuable due date field

See merge request gitlab-org/gitlab-ce!21751

Document how to enable/disable Auto DevOps at the instance level

Closes #49820

See merge request gitlab-org/gitlab-ce!21139

Update command-line-commands.md to include an sample taskflow

See merge request gitlab-org/gitlab-ce!21756

Improve docs about CI/CD config `extends`

See merge request gitlab-org/gitlab-ce!21669

CE: Properly implement prepending for Concern

See merge request gitlab-org/gitlab-ce!21444

Relax Danger requirements about changed lines

Closes gitlab-org/release/framework#13

See merge request gitlab-org/gitlab-ce!21739

Update GitLab Shell to v8.3.3

See merge request gitlab-org/gitlab-ce!21750

Cleaned up CI runner administration code

See merge request gitlab-org/gitlab-ce!21741

Remove peek-sidekiq

Closes #51407

See merge request gitlab-org/gitlab-ce!21693

Fix object storage uploads not working with AWS v2

Closes gitlab-workhorse#181

See merge request gitlab-org/gitlab-ce!21731

Fix karma junit result formatter

See merge request gitlab-org/gitlab-ce!21744

Because we were passing query strings as symbols, the fog-aws storage
driver was omitting the uploadId and partNumber query strings
from the signature in multipart uploads. This fix makes AWS and Ceph work with
v2 signatures.

See: https://github.com/fog/fog-aws/blob/v3.0.0/lib/fog/aws/storage.rb#L733

Closes https://gitlab.com/gitlab-org/gitlab-workhorse/issues/181

Fix typo in Danger message

See merge request gitlab-org/gitlab-ce!21746

Prevent premature failure on AutoDevOps Pipeline

Closes gitlab-qa#323

See merge request gitlab-org/gitlab-ce!21709