Update sigstore/cosign-installer action to v3.0.3

[renovate[bot]]

This PR contains the following updates:

Package	Type	Update	Change
sigstore/cosign-installer	action	patch	v3.0.2 -> v3.0.3

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Release Notes

sigstore/cosign-installer

### [`v3.0.3`](https://togithub.com/sigstore/cosign-installer/releases/tag/v3.0.3) [Compare Source](https://togithub.com/sigstore/cosign-installer/compare/v3.0.2...v3.0.3) ##### What's Changed - bump to cosign v2.0.2 by [@​bobcallaway](https://togithub.com/bobcallaway) in [https://github.com/sigstore/cosign-installer/pull/119](https://togithub.com/sigstore/cosign-installer/pull/119) **Full Changelog**: https://github.com/sigstore/cosign-installer/compare/v3.0.2...v3.0.3

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Configuration

📅 Schedule: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined).

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

♻ Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about this update again.

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• [ ] If you want to rebase/retry this PR, check this box

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