Disable the inheritance column of services in DisableInvalidServiceTemplates migration

Closes #28850

See merge request !9613

Replace create_new_project_button.png

See merge request !9403

Update docs to reflect Yarn support added in 8.17 not 9.0

See merge request !9590

Docs: Tags: Fix typo in parent_ids in example response

See merge request !9550

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>

Add note about how to use or escape variables inside other variables

See merge request !9601

Moved issue boards new issue form template

See merge request !9572

generalize the idea of a "unique internal user"

See merge request !9562

[ci skip]

Restructure pages docs

Closes #28688

See merge request !9527

#25437 Allow posting of just an emoji in comment; add /award slash command

Closes #25437

See merge request !9382

[ci skip]

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

add /award slash command; Allow posting of just an emoji in comment

Fix Cycle Analytics -> Plan is loading forever

Closes #27622

See merge request !9577

Since we will likely be needing this for other features, for example the
Gitlab ServiceDesk support bot.

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