Create patch to update DefaultWatchErrorHandler call for client-go

After bumping k8s.io/client-go, Prometheus started failing to build in the Kubernetes discovery package.

The error looks like this:

# github.com/prometheus/prometheus/discovery/kubernetes
.../kubernetes.go:862:36: not enough arguments in call to cache.DefaultWatchErrorHandler
    have (*cache.Reflector, error)
    want (context.Context, *cache.Reflector, error)

---

The signature of cache.DefaultWatchErrorHandler in k8s.io/client-go changed in v0.33.0:

• Before: func(r *cache.Reflector, err error)
• After: func(ctx context.Context, r *cache.Reflector, err error)

Prometheus Kubernetes discovery still called the old variant, which breaks the build after bumping client-go.

This patch updates informerWatchErrorHandler to pass a context to DefaultWatchErrorHandler. For now, we use context.Background(), which restores compatibility and aligns with the new function signature.

This change is required to build Prometheus with client-go >= v0.33.0.

Bug: https://bugs-devel.debian.org/cgi-bin/bugreport.cgi?bug=1113806

cc @gibmat