Update ghcr.io/fluxcd/kustomize-controller Docker tag to v0.13.0

This MR contains the following updates:

Package	Type	Update	Change
ghcr.io/fluxcd/kustomize-controller	ironbank-docker	minor	v0.12.2 -> v0.13.0
ghcr.io/fluxcd/kustomize-controller		minor	v0.12.2 -> v0.13.0
ghcr.io/fluxcd/kustomize-controller	stage	minor	v0.12.2 -> v0.13.0

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