chore(deps): update quay.io/cortexproject/cortex docker tag to v1.15.3

[renovate[bot]]

This PR contains the following updates:

Package	Update	Change
quay.io/cortexproject/cortex	patch	v1.15.2 -> v1.15.3

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Release Notes

cortexproject/cortex

### [`v1.15.3`](https://togithub.com/cortexproject/cortex/releases/tag/v1.15.3): Cortex 1.15.3 [Compare Source](https://togithub.com/cortexproject/cortex/compare/v1.15.2...v1.15.3) This release includes: - Distributor: Fix potential data corruption in cases of timeout between distributors and ingesters. [#​5422](https://togithub.com/cortexproject/cortex/issues/5422)

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