Capture running builds on non-shared runners

What does this MR do and why?

This MR expands the usage of Ci::RunningBuild.upsert_shared_runner_build! to capture all running builds, not only the ones running on shared runners. This will be needed for #437849 (closed).

I've added a FF to derisk .com deployment. Once we confirm that no adverse effects occurred from creating/destroying the additional Ci::RunningBuild instances, we can remove this FF (patch in rollout issue).

Looking at the production database, we're creating 1.1M records on a typical day. With this change, that will increase to almost 5M.

Changelog: changed

Closes #437846 (closed)

MR acceptance checklist

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How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

The tests already cover the changes performed. However, this can be tested by following the steps below:

1. Enable the FF in the GDK Rails console:

   Feature.enable(:add_all_ci_running_builds)
   Feature.enable(:remove_all_ci_running_builds)

2. Select a project in your GDK.

3. Create and register a project runner in that project with the tags: shell, gdk.

4. Edit the .gitlab-ci.yml to include the following content:

   default:
     tags:
       - shell
       - gdk
   
   build1:
     stage: build
     script:
       - echo "Do your build here"
       - sleep 300

5. Commit and ensure a pipeline is run.

6. On the GDK Rails console, confirm that the Ci::RunningBuild was created:

   > Ci::RunningBuild.where.not(runner_type: :instance_type).exists?
     Ci::RunningBuild Exists? (0.4ms)  SELECT 1 AS one FROM "ci_running_builds" WHERE "ci_running_builds"."runner_type" != 1 LIMIT 1 /*application:console,db_config_name:ci,console_hostname:gitlab-macbookpro.work.pombei.ro,console_username:pedropombeiro,line:(pry):12:in `__pry__'*/
   => true