Add `jobs_count` field to `LimitExceededError`

It will be useful to be able to perform filtering in Kibana based on the
number of jobs in a pipeline for pipelines that have exceeded either a
configured size limit or the unenforced default global limit of 2000.

https://gitlab.com/gitlab-org/gitlab/-/issues/285093

ee/lib/ee/gitlab/ci/pipeline/chain/limit/size.rb

@@ -39,6 +39,7 @@ module EE
 
               def log_attrs
                 {
+                  jobs_count: pipeline.statuses.count,
                   pipeline_source: pipeline.source,
                   plan: project.actual_plan_name,
                   project_id: project.id,

ee/spec/lib/gitlab/ci/pipeline/chain/limit/size_spec.rb

@@ -70,6 +70,7 @@ RSpec.describe ::Gitlab::Ci::Pipeline::Chain::Limit::Size do
       it 'logs the error' do
         expect(Gitlab::ErrorTracking).to receive(:log_exception).with(
           instance_of(Gitlab::Ci::Limit::LimitExceededError),
+          jobs_count: pipeline.statuses.count,
           project_id: project.id, plan: namespace.actual_plan_name,
           project_full_path: project.full_path, pipeline_source: pipeline.source
         )
@@ -152,6 +153,7 @@ RSpec.describe ::Gitlab::Ci::Pipeline::Chain::Limit::Size do
       it 'logs the pipeline' do
         expect(Gitlab::ErrorTracking).to receive(:log_exception).with(
           instance_of(Gitlab::Ci::Limit::LimitExceededError),
+          jobs_count: pipeline.statuses.count,
           project_id: project.id, plan: namespace.actual_plan_name,
           project_full_path: project.full_path, pipeline_source: pipeline.source
         )