Remove `ci_bridge_pipeline_details` feature flag

The feature is stable,
we no longer need this feature flag.

config/feature_flags/development/ci_bridge_pipeline_details.yml

----
-name: ci_bridge_pipeline_details
-introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/41263
-rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/250683
-group: group::memory
-type: development
-default_enabled: true

lib/gitlab/ci/status/bridge/common.rb

@@ -14,7 +14,6 @@ module Gitlab
           end
 
           def details_path
-            return unless Feature.enabled?(:ci_bridge_pipeline_details, subject.project, default_enabled: true)
             return unless can?(user, :read_pipeline, downstream_pipeline)
 
             project_pipeline_path(downstream_project, downstream_pipeline)

spec/lib/gitlab/ci/status/bridge/common_spec.rb

@@ -30,15 +30,6 @@ RSpec.describe Gitlab::Ci::Status::Bridge::Common do
 
       it { expect(subject).to have_details }
       it { expect(subject.details_path).to include "pipelines/#{downstream_pipeline.id}" }
-
-      context 'when ci_bridge_pipeline_details is disabled' do
-        before do
-          stub_feature_flags(ci_bridge_pipeline_details: false)
-        end
-
-        it { expect(subject).not_to have_details }
-        it { expect(subject.details_path).to be_nil }
-      end
     end
 
     context 'when user does not have access to read downstream pipeline' do