Update sigstore/cosign-installer action to v3.8.1

[renovate-bot]

This PR contains the following updates:

Package	Type	Update	Change
sigstore/cosign-installer	action	minor	v3.5.0 -> v3.8.1

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Release Notes

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

v3.8.1

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What's Changed

• use cosign 2.4.3 and other updates by @​cpanato in https://github.com/sigstore/cosign-installer/pull/182

Full Changelog: sigstore/cosign-installer@v3...v3.8.1

v3.8.0

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What's Changed

• test action against all non-rc releases, verify entry in rekor log by @​bobcallaway in https://github.com/sigstore/cosign-installer/pull/179
• bump for cosign v2.4.2 release by @​bobcallaway in https://github.com/sigstore/cosign-installer/pull/181

Full Changelog: sigstore/cosign-installer@v3...v3.8.0

v3.7.0

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What's Changed

• Bump actions/checkout from 4.1.7 to 4.2.0 by @​dependabot in https://github.com/sigstore/cosign-installer/pull/172
• bump for latest cosign v2.4.1 release by @​bobcallaway in https://github.com/sigstore/cosign-installer/pull/173

Full Changelog: sigstore/cosign-installer@v3.6.0...v3.7.0

v3.6.0

Compare Source

What's Changed

• Bump actions/checkout from 4.1.2 to 4.1.3 by @​dependabot in https://github.com/sigstore/cosign-installer/pull/161
• Bump actions/checkout from 4.1.3 to 4.1.4 by @​dependabot in https://github.com/sigstore/cosign-installer/pull/162
• Bump actions/setup-go from 5.0.0 to 5.0.1 by @​dependabot in https://github.com/sigstore/cosign-installer/pull/163
• Bump actions/checkout from 4.1.4 to 4.1.5 by @​dependabot in https://github.com/sigstore/cosign-installer/pull/164
• Bump actions/checkout from 4.1.5 to 4.1.6 by @​dependabot in https://github.com/sigstore/cosign-installer/pull/165
• Bump actions/checkout from 4.1.6 to 4.1.7 by @​dependabot in https://github.com/sigstore/cosign-installer/pull/166
• Bump actions/setup-go from 5.0.1 to 5.0.2 by @​dependabot in https://github.com/sigstore/cosign-installer/pull/167
• pin public key used for verification by @​bobcallaway in https://github.com/sigstore/cosign-installer/pull/169
• bump default version to v2.4.0 release by @​bobcallaway in https://github.com/sigstore/cosign-installer/pull/168
• update readme for new release by @​bobcallaway in https://github.com/sigstore/cosign-installer/pull/170

Full Changelog: sigstore/cosign-installer@v3...v3.6.0

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