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/apiserver/aggregatorrunner/noopaggregator.go

@@ -0,0 +1,26 @@
+package aggregatorrunner
+
+import (
+	"context"
+
+	"k8s.io/apimachinery/pkg/runtime"
+	genericapiserver "k8s.io/apiserver/pkg/server"
+
+	"github.com/grafana/grafana/pkg/services/apiserver/builder"
+	"github.com/grafana/grafana/pkg/services/apiserver/options"
+)
+
+type NoopAggregatorConfigurator struct {
+}
+
+func (n NoopAggregatorConfigurator) Configure(opts *options.Options, config *genericapiserver.RecommendedConfig, delegateAPIServer genericapiserver.DelegationTarget, scheme *runtime.Scheme, builders []builder.APIGroupBuilder) (*genericapiserver.GenericAPIServer, error) {
+	return nil, nil
+}
+
+func (n NoopAggregatorConfigurator) Run(ctx context.Context, transport *options.RoundTripperFunc, stoppedCh chan error) (*genericapiserver.GenericAPIServer, error) {
+	return nil, nil
+}
+
+func ProvideNoopAggregatorConfigurator() AggregatorRunner {
+	return &NoopAggregatorConfigurator{}
+}

pkg/services/apiserver/aggregatorrunner/runner.go

@@ -0,0 +1,24 @@
+package aggregatorrunner
+
+import (
+	"context"
+
+	"k8s.io/apimachinery/pkg/runtime"
+	genericapiserver "k8s.io/apiserver/pkg/server"
+
+	"github.com/grafana/grafana/pkg/services/apiserver/builder"
+	"github.com/grafana/grafana/pkg/services/apiserver/options"
+)
+
+// AggregatorRunner is an interface for running an aggregator inside the same generic apiserver delegate chain
+type AggregatorRunner interface {
+	// Configure is called to configure the component and returns the delegate for further chaining.
+	Configure(opts *options.Options,
+		config *genericapiserver.RecommendedConfig,
+		delegateAPIServer genericapiserver.DelegationTarget,
+		scheme *runtime.Scheme,
+		builders []builder.APIGroupBuilder) (*genericapiserver.GenericAPIServer, error)
+
+	// Run starts the complete apiserver chain, expects it executes any logic inside a goroutine and doesn't block. Returns the running server.
+	Run(ctx context.Context, transport *options.RoundTripperFunc, stoppedCh chan error) (*genericapiserver.GenericAPIServer, error)
+}