chore: add experiment toggle for terraform workspace caching (#20559)

Experiments passed to provisioners to determine behavior. This adds
`--experiments` flag to provisioner daemons. Prior to this, provisioners
had no method to turn on/off experiments.

coderd/provisionerdserver/provisionerdserver.go

@@ -121,6 +121,7 @@ type server struct {
 	NotificationsEnqueuer       notifications.Enqueuer
 	PrebuildsOrchestrator       *atomic.Pointer[prebuilds.ReconciliationOrchestrator]
 	UsageInserter               *atomic.Pointer[usage.Inserter]
+	Experiments                 codersdk.Experiments
 
 	OIDCConfig promoauth.OAuth2Config
 
@@ -182,6 +183,7 @@ func NewServer(
 	enqueuer notifications.Enqueuer,
 	prebuildsOrchestrator *atomic.Pointer[prebuilds.ReconciliationOrchestrator],
 	metrics *Metrics,
+	experiments codersdk.Experiments,
 ) (proto.DRPCProvisionerDaemonServer, error) {
 	// Fail-fast if pointers are nil
 	if lifecycleCtx == nil {
@@ -253,6 +255,7 @@ func NewServer(
 		PrebuildsOrchestrator:       prebuildsOrchestrator,
 		UsageInserter:               usageInserter,
 		metrics:                     metrics,
+		Experiments:                 experiments,
 	}
 
 	if s.heartbeatFn == nil {

coderd/provisionerdserver/provisionerdserver_test.go

@@ -26,6 +26,7 @@ import (
 	"storj.io/drpc"
 
 	"cdr.dev/slog/sloggers/slogtest"
+	"github.com/coder/coder/v2/coderd"
 	"github.com/coder/coder/v2/coderd/util/ptr"
 	"github.com/coder/quartz"
 	"github.com/coder/serpent"
@@ -4162,7 +4163,7 @@ func setup(t *testing.T, ignoreLogErrors bool, ov *overrides) (proto.DRPCProvisi
 	defOrg, err := db.GetDefaultOrganization(context.Background())
 	require.NoError(t, err, "default org not found")
 
-	deploymentValues := &codersdk.DeploymentValues{}
+	deploymentValues := coderdtest.DeploymentValues(t)
 	var externalAuthConfigs []*externalauth.Config
 	tss := testTemplateScheduleStore()
 	uqhss := testUserQuietHoursScheduleStore()
@@ -4285,6 +4286,7 @@ func setup(t *testing.T, ignoreLogErrors bool, ov *overrides) (proto.DRPCProvisi
 		notifEnq,
 		&op,
 		provisionerdserver.NewMetrics(logger),
+		coderd.ReadExperiments(logger, deploymentValues.Experiments),
 	)
 	require.NoError(t, err)
 	return srv, db, ps, daemon