revert to go 1.21 & k8s client 0.29.4

Dockerfile

go.mod

go.sum

scripts/generators.Dockerfile

vendor/github.com/go-logr/logr/slogr/slogr.go

vendor/golang.org/x/net/websocket/client.go

vendor/golang.org/x/net/websocket/dial.go

vendor/golang.org/x/net/websocket/hybi.go

vendor/golang.org/x/net/websocket/server.go

vendor/golang.org/x/net/websocket/websocket.go

vendor/k8s.io/api/admissionregistration/v1/generated.pb.go

vendor/k8s.io/api/admissionregistration/v1/generated.proto

vendor/k8s.io/api/admissionregistration/v1/register.go

vendor/k8s.io/api/admissionregistration/v1/types.go

...i/admissionregistration/v1/types_swagger_doc_generated.go

....io/api/admissionregistration/v1/zz_generated.deepcopy.go

...k8s.io/api/admissionregistration/v1alpha1/generated.pb.go

.../k8s.io/api/admissionregistration/v1beta1/generated.pb.go

.../k8s.io/api/admissionregistration/v1beta1/generated.proto

vendor/k8s.io/api/admissionregistration/v1beta1/types.go