Bump the deprecated FluxCD versions

[moconnor-cni]

Issues

This PR addresses the following issue

• Installation using deprecated FluxCD APIs #1538

Testing

Installed the operator using the revised script. Note the warnings no longer appear.

% kubectl apply -f https://raw.githubusercontent.com/moconnor-cni/tofu-controller/refs/heads/main/docs/release.yaml
helmrepository.source.toolkit.fluxcd.io/tofu-controller created
helmrelease.helm.toolkit.fluxcd.io/tofu-controller created

The operator is installed as expected

% kubectl -n flux-system get helmrepository,helmrelease
NAME                                                      URL                                          AGE     READY   STATUS
helmrepository.source.toolkit.fluxcd.io/tofu-controller   https://flux-iac.github.io/tofu-controller   3m17s   True    stored artifact: revision 'sha256:d9d77a5cdbb5518fa9936a62fdda619f65ba3e08c48b11f4c6abdf50391f3d1e'

NAME                                                 AGE     READY   STATUS
helmrelease.helm.toolkit.fluxcd.io/tofu-controller   3m17s   True    Helm install succeeded for release flux-system/tofu-controller.v1 with chart tofu-controller@0.16.0-rc.5