instead of having the explicit logic duplicated from the scope we can
use the scope instead.

the scope `Ci::Runner.belonging_to_group` does not filter out the
runners where the projects has `#group_runners_enabled` set to false
anymore.

it didn't show up in the runners UI anymore when group runners were
disabled. this was confusing.

the flag is only relevant when selecting appropriate runner for a build.

1. we don't want to migrate all existing groups
2. we generate the token when showing the runners page, as this is the
   first time that the token will be used.

as we're using UNION now we can use INNER JOIN.

the unions performs much better than the joins, and the execution time
is constant with a growing number of records.

Removes  'Job log message' from build trace

Closes #45625

See merge request gitlab-org/gitlab-ce!18523

'No job log' message is no longer necessary since we returned an image
when a build does not have a trace. See
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/18278 for more
details

Closes #45625

Dedupe yarn dependencies

See merge request gitlab-org/gitlab-ce!18477

Downgrade MySQL CI service from 8.0 to 5.7

Closes #45606

See merge request gitlab-org/gitlab-ce!18512

add restart of gitlab-pages to apply gitlab pages settings

See merge request gitlab-org/gitlab-ce!18455

MySQL 8.0 made the default authentication mode `caching_sha2_password`, and
this breaks our CI builds at the moment. Downgrade until we can figure
out how to support this.

Closes #45606

Atomic internal ids for all models

Closes #44259

See merge request gitlab-org/gitlab-ce!18402

Add documentation on how to configure Redis Sentinel by persistent class

See merge request gitlab-org/gitlab-ce!18441

Don't include lfs_file_locks data in export bundle

Closes #45502

See merge request gitlab-org/gitlab-ce!18495

Add an API endpoint to download git repository snapshots

Closes #39345

See merge request gitlab-org/gitlab-ce!18173

Resolve "Show new branch/merge request button even if a branch / merge request already exists"

Closes #42803

See merge request gitlab-org/gitlab-ce!17712

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