Make username update fail if namespace update fails

Closes gitlab-com/support-forum#2316

See merge request !13642

Fix broken Yarn dependencies

Closes #33886 and #34944

See merge request !13614

Resolve "Failing karma tests for Chrome 60"

Closes #36517

See merge request !13646

Remove superfluous users bundle

See merge request !13684

Fixed issue boards closed list displaying empty label

Closes #36650

See merge request !13658

Refactor GPG docs

See merge request !13660

Update Create Project Getting Started

See merge request !13687

Fix Error 500s when attempting to destroy a protected tag

Closes #36013

See merge request !13692

Due to a missing `on_delete: :cascade`, users would hit the error that
looked like:

```
PG::ForeignKeyViolation: ERROR: update or delete on table "protected_tags"
violates foreign key constraint "fk_rails_f7dfda8c51" on table
"protected_tag_create_access_levels" DETAIL: Key (id)=(1385) is still
referenced from table "protected_tag_create_access_levels". : DELETE FROM
"protected_tags" WHERE "protected_tags"."id" = 1385
```

Closes #36013

1. Generating a GPG key
1. Signing commits
1. Associating a GPG key with Git

Make issuable filter dropdown style consistent

See merge request !13421

Correct repo.vue template

Closes #36415

See merge request !13452

Add current locale to commit partial cache key

Closes #36591

See merge request !13669

Merge branch 'pawel/update_prometheus_client_gem_to_improve_performance_when_rendering_metrics' into 'master'

Update prometheus mmap client library to fix performance issues when rendering many metrics.

See merge request !13674

Migrating from Clearcase docs

See merge request !13569

Merge branch '36630-activerecord-statementinvalid-pg-notnullviolation-error-null-value-in-column-a_mode-violates-not-null-constraint' into 'master'

Resolve "ActiveRecord::StatementInvalid: PG::NotNullViolation: ERROR:  null value in column "a_mode" violates not-null constraint"

Closes #36630

See merge request !13663

[ci skip]

Describe the supported version of group-level variables API in document

Closes #36543

See merge request !13648

Update project_snippets.md

See merge request !13654

Guess the modes based on the following:

1. If the file didn't exist, it's zero.
2. If the diff contains 'Subproject commit', it might be a submodule, so 0600.
3. Otherwise, it's 0644.

This isn't perfect, but it doesn't have to be - it won't change file modes in
the repository.

Client Implementation: RefService::RefExists

Closes gitaly#452

See merge request !13528

Fix unnecessarily long gl.utils.backOff test

Closes #36648

See merge request !13651

Add support for i18n on Project Activity Page

Closes #32795

See merge request !13451

Closes #36650

Setup settings properly

See merge request !13645

Don't escape html entities in InlineDiffMarkdownMarker

Closes #36041

See merge request !13553