Show pre-receive error message in merge request widget

Closes gitlab-ee#10165

See merge request gitlab-org/gitlab-ce!25708

When a merge fails due to a locked file, no feedback was given to the
user as to why it failed if the user used the Merge button.  However, if
the push attempt happened directly in the Web UI, the pre-receive
message would be displayed.

To be consistent and to make it clear why a merge failed, we now include
the pre-receive error message in the merge request widget.

Closes https://gitlab.com/gitlab-org/gitlab-ee/issues/10165

Removing old code path for search_files_by_content

See merge request gitlab-org/gitlab-ce!25617

Eliminate most N+1 queries loading UserController#calendar_activities

Closes #58392

See merge request gitlab-org/gitlab-ce!25697

In 11.8, we added a fix for the SearchFilesByContent RPC in gitaly to
send back the response in chunks. However, we kept in the old code path
for backwards compatibility. Now that the change is fully deployed, we
can remove that old codepath.

Bump Bootsnap to 1.4.1

See merge request gitlab-org/gitlab-ce!25701

1.4.1 contains a number of bug fixes and performance improvements:
https://github.com/Shopify/bootsnap/blob/master/CHANGELOG.md

Resolve "Github importer ignores Milestone due_date"

Closes #57612

See merge request gitlab-org/gitlab-ce!25182

Fix commenting on epics permissions

Closes #9023

See merge request gitlab-org/gitlab-ee!9783

Fix bridge jobs than can be hidden keys too

Closes gitlab-ce#58358

See merge request gitlab-org/gitlab-ee!9796

Badge and improve limits topic

See merge request gitlab-org/gitlab-ee!9758

Fix some 404 links into charts project

See merge request gitlab-org/gitlab-ce!25589

Add quick link to GitLab.com settings

See merge request gitlab-org/gitlab-ce!25580

Add confidential issue linking guidance

See merge request gitlab-org/gitlab-ce!25326

We can reduce a significant number of queries by preloading the
associations for events.

On GitLab.com, for a date that had 456 events, this brought the load
time down from 8.7 to 1.2 s.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/58392

Merge branch '10138-cannot-drop-index-index_prometheus_alerts_on_project_id_and_prometheus_metric_id-needed-in-a-foreign-key-constraint' into 'master'

Resolve "Cannot drop index 'index_prometheus_alerts_on_project_id_and_prometheus_metric_id': needed in a foreign key constraint"

Closes #10138

See merge request gitlab-org/gitlab-ee!9792

Fix GitLab::JsonCache when reading a persisted entry back from the cache

See merge request gitlab-org/gitlab-ce!25587

Create pool repositories on Geo secondaries

See merge request gitlab-org/gitlab-ee!9428

Resolves "Geo - Selective sync by namespace is broken"

Closes #10041 and #9903

See merge request gitlab-org/gitlab-ee!9732

Hashed Storage rollback mechanism

See merge request gitlab-org/gitlab-ce!23955

Update Serverless docs with livestream feedback

See merge request gitlab-org/gitlab-ce!25616

MySQL requires to drop FK for time of re-adding index

Add suffix (`_event`) to merge request source

Closes gitlab-ee#9893

See merge request gitlab-org/gitlab-ce!25508