Update sigstore/cosign-installer action to v3.1.2

[renovate[bot]]

This PR contains the following updates:

Package	Type	Update	Change
sigstore/cosign-installer	action	patch	v3.1.1 -> v3.1.2

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Release Notes

sigstore/cosign-installer (sigstore/cosign-installer)

### [`v3.1.2`](https://togithub.com/sigstore/cosign-installer/releases/tag/v3.1.2) [Compare Source](https://togithub.com/sigstore/cosign-installer/compare/v3.1.1...v3.1.2) #### What's Changed - Fix build and push step Readme missing id by [@​hbenali](https://togithub.com/hbenali) in [https://github.com/sigstore/cosign-installer/pull/138](https://togithub.com/sigstore/cosign-installer/pull/138) - bump cosign to v2.2.0 by [@​cpanato](https://togithub.com/cpanato) in [https://github.com/sigstore/cosign-installer/pull/142](https://togithub.com/sigstore/cosign-installer/pull/142) #### New Contributors - [@​hbenali](https://togithub.com/hbenali) made their first contribution in [https://github.com/sigstore/cosign-installer/pull/138](https://togithub.com/sigstore/cosign-installer/pull/138) **Full Changelog**: https://github.com/sigstore/cosign-installer/compare/v3...v3.1.2

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