Implement autobackup-operator controllers, tests, CI and packaging

PVCs and CloudNativePG Clusters need S3 buckets and backup schedules
provisioned consistently. This operator watches the
backups.unkin.net/{schedule,destination} annotations on those objects and
provisions everything needed to back them up, with no new CRDs.

- Add a PVC controller that provisions cephrgw ObjectStoreUser/Bucket/BucketAccess,
  auto-generates a restic repo-password Secret and creates a k8up Schedule scoped
  to the PVC via spec.backup.volumes[].persistentVolumeClaim.claimName.
- Add a CNPG Cluster controller that provisions the same bucket stack, idempotently
  patches spec.backup.barmanObjectStore (leaving a user-set destinationPath alone
  with a Warning event) and creates a ScheduledBackup.
- Resolve destinations through a ConfigMap lookup table; requeue until the
  BucketAccess is Ready before creating schedule resources; own-reference created
  resources and retain bucket data by default.
- Add schedule-mapping helpers (k8up 5-field/shortcut pass-through, CNPG 6-field
  seconds-first) and deterministic, length-bounded name derivation.
- Add unit tests (schedule mapping, name derivation, destination resolution) and
  envtest controller tests for both paths, wiring the external CRDs into envtest.
- Add kubebuilder-generated RBAC, a Dockerfile (distroless/nonroot), Woodpecker
  lint/test/build pipelines and a tag-triggered image push to the artifactapi
  docker-internal registry, plus a version-bump Makefile and deploy manifests.

vendor/github.com/google/gnostic-models/compiler/error.go

@@ -0,0 +1,70 @@
+// Copyright 2017 Google LLC. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package compiler
+
+import "fmt"
+
+// Error represents compiler errors and their location in the document.
+type Error struct {
+	Context *Context
+	Message string
+}
+
+// NewError creates an Error.
+func NewError(context *Context, message string) *Error {
+	return &Error{Context: context, Message: message}
+}
+
+func (err *Error) locationDescription() string {
+	if err.Context.Node != nil {
+		return fmt.Sprintf("[%d,%d] %s", err.Context.Node.Line, err.Context.Node.Column, err.Context.Description())
+	}
+	return err.Context.Description()
+}
+
+// Error returns the string value of an Error.
+func (err *Error) Error() string {
+	if err.Context == nil {
+		return err.Message
+	}
+	return err.locationDescription() + " " + err.Message
+}
+
+// ErrorGroup is a container for groups of Error values.
+type ErrorGroup struct {
+	Errors []error
+}
+
+// NewErrorGroupOrNil returns a new ErrorGroup for a slice of errors or nil if the slice is empty.
+func NewErrorGroupOrNil(errors []error) error {
+	if len(errors) == 0 {
+		return nil
+	} else if len(errors) == 1 {
+		return errors[0]
+	} else {
+		return &ErrorGroup{Errors: errors}
+	}
+}
+
+func (group *ErrorGroup) Error() string {
+	result := ""
+	for i, err := range group.Errors {
+		if i > 0 {
+			result += "\n"
+		}
+		result += err.Error()
+	}
+	return result
+}