Speed up `all_commit_shas` for new merge requests

See merge request !12706

Resolve "Inconsistent location of members page between groups and projects"

Closes #29893

See merge request !11560

N+1 problems on milestone page

Closes #34736

See merge request !12670

This makes the `Boards::CreateService` more reusable for EE

See merge request !12704

Follow-up from "Namespace license checks for multiple assignees"

Closes gitlab-ee#2839

See merge request !12701

Refactor several javascript files to ES module syntax

See merge request !12683

Fix ShaAttribute concern when there is no table

Closes #34798

See merge request !12705

For merge requests created after 9.4, we have a `merge_request_diff_commits`
table we can get all the SHAs from very quickly. We just need to exclude these
when we load from the legacy format, by ignoring diffs with no serialised
commits.

Once these have been migrated in the background, every MR will see this
improvement.

Add Group secret variables

Closes #12729

See merge request !12582

Remove option to disable Gitaly in Rails

See merge request !12677

When this is added to a new model, it would fail before the migrations were run
- including when trying to run migrations in production mode!

Update VERSION to 9.4.0-pre.

See merge request !12702

Extend MR tabs a bit to cover up the avatar holder and collapse icon on scroll

Closes #34153

See merge request !12589

Don't show auxiliary blob viewer for README when there is no wiki

Closes #34732

See merge request !12689

Upgrade GitLab Pages to v0.5.0

See merge request !12625

/reassign should only work when multiple assignees are available. And
since this is only the case for GitLab EE, remove it from CE.

This was picked using 517c97eb of gitlab-ee.

They are confusing.

Adopt project_variable_path instead of namespace_project_variable_path. (Resolve confilct from master)

[ci skip]

Fix static-snalysis

Move the precedence of group secure variable before project secure variable. Allow project_id to be null.

Separate Ci::VariableProject and Ci::VariableGroup

Add the forgotton files

Add migration file to update type of ci_variables

Fix form_for fpr VariableProject

Fix test

Change the table structure according to the yorik advice

Add necessary migration files. Remove unnecessary migration spec.

Revert safe_model_attributes.yml

Fix models

Fix spec

Avoid self.variable. Use becomes for correct routing.

Use unique index on group_id and key

Add null: false for t.timestamps

Fix schema version

Rename VariableProject and VariableGroup to ProjectVariable and GroupVariable

Rename the rest of them

Add the rest of files

Basic BE change

Fix static-snalysis

Move the precedence of group secure variable before project secure variable. Allow project_id to be null.

Separate Ci::VariableProject and Ci::VariableGroup

Add the forgotton files

Add migration file to update type of ci_variables

Fix form_for fpr VariableProject

Fix test

Change the table structure according to the yorik advice

Add necessary migration files. Remove unnecessary migration spec.

Revert safe_model_attributes.yml

Fix models

Fix spec

Avoid self.variable. Use becomes for correct routing.

Use unique index on group_id and key

Add null: false for t.timestamps

Fix schema version

Rename VariableProject and VariableGroup to ProjectVariable and GroupVariable

Rename the rest of them

Add the rest of files

Implement CURD

Rename codes related to VariableGroup and VariableProject FE part

Remove unneccesary changes

Make Fe code up-to-date

Add protected flag to migration file

Protected group variables essential package

Update schema

Improve doc

Fix logic and spec for models

Fix logic and spec for controllers

 Fix logic and spec for views(pre feature)

Add feature spec

Fixed bugs. placeholder. reveal button. doc.

Add changelog

Remove unnecessary comment

godfat nice catches

Improve secret_variables_for arctecture

Fix spec

Fix StaticAnlysys & path_regex spec

Revert "Improve secret_variables_for arctecture"

This reverts commit c3216ca212322ecf6ca534cb12ce75811a4e77f1.

Use ayufan suggestion for secret_variables_for

Use find instead of find_by

Fix spec message for variable is invalid

Fix spec remove variable.group_id = group.id

godffat spec nitpicks

Use include Gitlab::Routing.url_helpers for presenter spec