rebase: Bump sigs.k8s.io/controller-runtime

Bumps [sigs.k8s.io/controller-runtime](https://github.com/kubernetes-sigs/controller-runtime) from 0.15.1-0.20230524200249-30eae58f1b98 to 0.15.1.
- [Release notes](https://github.com/kubernetes-sigs/controller-runtime/releases)
- [Changelog](https://github.com/kubernetes-sigs/controller-runtime/blob/main/RELEASE.md)
- [Commits](https://github.com/kubernetes-sigs/controller-runtime/commits/v0.15.1)

---
updated-dependencies:
- dependency-name: sigs.k8s.io/controller-runtime
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

vendor/sigs.k8s.io/controller-runtime/pkg/cache/cache.go

@@ -236,6 +236,11 @@ func New(config *rest.Config, opts Options) (Cache, error) {
 }
 
 func defaultOpts(config *rest.Config, opts Options) (Options, error) {
+	config = rest.CopyConfig(config)
+	if config.UserAgent == "" {
+		config.UserAgent = rest.DefaultKubernetesUserAgent()
+	}
+
 	logger := log.WithName("setup")
 
 	// Use the rest HTTP client for the provided config if unset