Update ghcr.io/fluxcd/kustomize-controller Docker tag to v0.13.1

This MR contains the following updates:

Package	Type	Update	Change
ghcr.io/fluxcd/kustomize-controller	ironbank-docker	patch	v0.13.0 -> v0.13.1
ghcr.io/fluxcd/kustomize-controller		patch	v0.13.0 -> v0.13.1
ghcr.io/fluxcd/kustomize-controller	stage	patch	v0.13.0 -> v0.13.1

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