Update the "max reconciles" for each controller to 25 (#724)

<!--Thanks for your contribution. See [CONTRIBUTING](CONTRIBUTING.md)
    for Pulumi's contribution guidelines.

    Help us merge your changes more quickly by adding more details such
    as labels, milestones, and reviewers.-->

### Proposed changes

<!--Give us a brief description of what you've done and what it solves.
-->

Use 25 by default to facilitate the blocking operations in the auto API,
and support the `MAX_CONCURRENT_RECONCILES` environment variable.

### Related issues (optional)

<!--Refer to related PRs or issues: #1234, or 'Fixes #1234' or 'Closes
#1234'.
Or link to full URLs to issues or pull requests in other GitHub
repositories. -->

operator/cmd/main.go

@@ -23,6 +23,7 @@ import (
 	"net"
 	"net/http"
 	"os"
+	"strconv"
 
 	// Import all Kubernetes client auth plugins (e.g. Azure, GCP, OIDC, etc.)
 	// to ensure that exec-entrypoint and run can make use of them.
@@ -34,6 +35,7 @@ import (
 	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
 	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
 	ctrl "sigs.k8s.io/controller-runtime"
+	"sigs.k8s.io/controller-runtime/pkg/config"
 	"sigs.k8s.io/controller-runtime/pkg/healthz"
 	"sigs.k8s.io/controller-runtime/pkg/log/zap"
 	"sigs.k8s.io/controller-runtime/pkg/metrics/filters"
@@ -145,9 +147,17 @@ func main() {
 		metricsServerOptions.FilterProvider = filters.WithAuthenticationAndAuthorization
 	}
 
+	controllerOpts := config.Controller{
+		MaxConcurrentReconciles: 25,
+	}
+	if s, ok := os.LookupEnv("MAX_CONCURRENT_RECONCILES"); ok {
+		controllerOpts.MaxConcurrentReconciles, _ = strconv.Atoi(s)
+	}
+
 	mgr, err := ctrl.NewManager(ctrl.GetConfigOrDie(), ctrl.Options{
 		Scheme:                 scheme,
 		Metrics:                metricsServerOptions,
+		Controller:             controllerOpts,
 		WebhookServer:          webhookServer,
 		HealthProbeBindAddress: probeAddr,
 		LeaderElection:         enableLeaderElection,

operator/internal/controller/pulumi/stack_controller.go

@@ -26,7 +26,6 @@ import (
 	"os"
 	"path"
 	"slices"
-	"strconv"
 	"strings"
 	"sync"
 	"time"
@@ -70,10 +69,9 @@ var (
 )
 
 const (
-	pulumiFinalizer                = "finalizer.stack.pulumi.com"
-	defaultMaxConcurrentReconciles = 10
-	programRefIndexFieldName       = ".spec.programRef.name"      // this is an arbitrary string, named for the field it indexes
-	fluxSourceIndexFieldName       = ".spec.fluxSource.sourceRef" // an arbitrary name, named for the field it indexes
+	pulumiFinalizer          = "finalizer.stack.pulumi.com"
+	programRefIndexFieldName = ".spec.programRef.name"      // this is an arbitrary string, named for the field it indexes
+	fluxSourceIndexFieldName = ".spec.fluxSource.sourceRef" // an arbitrary name, named for the field it indexes
 )
 
 const (
@@ -89,14 +87,6 @@ func (r *StackReconciler) SetupWithManager(mgr ctrl.Manager) error {
 	blder := ctrl.NewControllerManagedBy(mgr).Named("stack-controller")
 	opts := controller.Options{}
 
-	opts.MaxConcurrentReconciles = defaultMaxConcurrentReconciles
-	if maxConcurrentReconcilesStr, ok := os.LookupEnv("MAX_CONCURRENT_RECONCILES"); ok {
-		opts.MaxConcurrentReconciles, err = strconv.Atoi(maxConcurrentReconcilesStr)
-		if err != nil {
-			return err
-		}
-	}
-
 	// Filter for update events where an object's metadata.generation is changed (no spec change!),
 	// or the "force reconcile" annotation is used (and not marked as handled).
 	predicates := []predicate.Predicate{