fix(helm): update chart cilium to 1.15.6

[renovate[bot]]

This PR contains the following updates:

Package	Type	Update	Change
cilium (source)	HelmChart	patch	1.15.5 -> 1.15.6
cilium (source)		patch	1.15.5 -> 1.15.6

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Release Notes

cilium/cilium (cilium)

### [`v1.15.6`](https://togithub.com/cilium/cilium/compare/1.15.5...1.15.6) [Compare Source](https://togithub.com/cilium/cilium/compare/1.15.5...1.15.6)

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