chore(deps): bump github.com/sigstore/cosign/v2 in /tools

Bumps [github.com/sigstore/cosign/v2](https://github.com/sigstore/cosign) from 2.2.4 to 2.6.2.
- [Release notes](https://github.com/sigstore/cosign/releases)
- [Changelog](https://github.com/sigstore/cosign/blob/main/CHANGELOG.md)
- [Commits](sigstore/cosign@v2.2.4...v2.6.2)

---
updated-dependencies:
- dependency-name: github.com/sigstore/cosign/v2
  dependency-version: 2.6.2
  dependency-type: indirect
...

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Author: dependabot[bot]