Remove kube-aggregator from OSS (#103659)

* feat: remove kube-aggregator for OSS and provide injection points with runner iface

* upgrade authlib to support expiresIn

* new FT

* new FT again

* update go.mod

* get rid of the slice implementation

* reconcile conflicts

* gracefully handle enterprise not being linked situation with kubeAggregator FT true

* allow dataplane agg and kube agg to both be added to delegate chain

* make update-workspace

* address feedback

* revert go.mod changes

* go.mod updates

* elaborate on why and how of skipping the Ready channel handling

* after rebase and make run

pkg/services/featuremgmt/toggles_gen.csv

@@ -114,6 +114,7 @@ groupToNestedTableTransformation,GA,@grafana/dataviz-squad,false,false,true
 newPDFRendering,GA,@grafana/sharing-squad,false,false,false
 tlsMemcached,GA,@grafana/grafana-operator-experience-squad,false,false,false
 kubernetesAggregator,experimental,@grafana/grafana-app-platform-squad,false,true,false
+kubernetesAggregatorCapTokenAuth,experimental,@grafana/grafana-app-platform-squad,false,true,false
 expressionParser,experimental,@grafana/grafana-app-platform-squad,false,true,false
 groupByVariable,experimental,@grafana/dashboards-squad,false,false,false
 scopeFilters,experimental,@grafana/dashboards-squad,false,false,false