The `unless defined?(Service)` was useless since in production env,
models are eager loaded, thus we wouldn't disable the STI, resulting in
the following error:

The single-table inheritance mechanism failed to locate the subclass:
'GitlabCiService'. This error is raised because the column 'type' is
reserved for storing the class in case of inheritance. Please rename
this column if you didn't intend it to be used for storing the
inheritance class or overwrite Service.inheritance_column to use another
column for that
information./opt/gitlab/embedded/service/gitlab-rails/db/post_migrate/20170211073944_disable_invalid_service_templates.rb:11:in `up'
Signed-off-by: Rémy Coutable <remy@rymai.me>

Fix todos API endpoint application error

Closes #22951

See merge request !9351

Remove help from right dropdown

Closes #28837

See merge request !9594

But notice first.

See merge request !9364

[ci skip]

Grammar improvement in gitlab flow intro doc

Closes #28696

See merge request !9552

Fix concurrent access on builds/register

See merge request !9600

Don't declare constants in Struct

Closes #28808

See merge request !9582

Pagination only changes the page parameter.

Closes #28818

See merge request !9581

Show milestone ID in a consistent way

Closes #23602

See merge request !8820

Move all Pages related content to a single location

Closes #28819 and #28714

See merge request !9583

Fix Cycle Analytics -> Plan is loading forever

Closes #27622

See merge request !9577

Move `Group -> Members` to top-level, fix missing sub-nav for Subgroups

Closes #28678

See merge request !9589

Left align logo; increase max width of title

Closes #27934

See merge request !9588

Fix CI tables action buttons are hidden is smaller screens

Closes #28661

See merge request !9578

Document use of AirBnb js styleguide and eslint.

See merge request !9558

Fix 'New Tag' layout on Tags page

See merge request !9176

Signed-off-by: Rémy Coutable <remy@rymai.me>

API project create: Make name or path required

Closes #6073

See merge request !9416

Checks if key is present before accessing it

Fix broken test

Fix broken test

[ci skip]

Don't allow a project to be shared with an ancestor of the group it is in

Closes #28788

See merge request !9566

Put back the new project button

Closes #27354

See merge request !9426

Fix access to projects shared with a nested group

Closes #28787

See merge request !9565

Ignore builds dir when run rubocop check

See merge request !9580

Merge branch '28769-raise-custom-exception-in-all-methods-of-mergeservice-that-want-to-inform-the-user' into 'master'

Use exceptions for MergeService error handling

Closes #28769

See merge request !9576

Return 204 on all DELETE endpoints

Closes #20429

See merge request !9397

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>