Update dependency dev.sigstore:protobuf-specs to v0.4.0

[renovate]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
dev.sigstore:protobuf-specs	0.3.3 -> 0.4.0

---

Release Notes

sigstore/protobuf-specs (dev.sigstore:protobuf-specs)

v0.4.0

• Announced deprecation of JSONSchema outputs from this project
  (#​493

Fixed

• Fix toolchain to write generated code as the user running the build instead of root
  (#​473

Changed

• Recreated toolchain for code generation instead of depending on third-party container image
  (#​469
  (#​475
• Updated code generation tools for Go library to latest stable releases
  (#​476
• Updated code generation tools for JSONSchema files to latest stable releases
  (#​478
• Updated code generation tools for Python library to latest stable releases
  (#​479
• Updated code generation tools for Ruby library to latest stable releases
  (#​481
• Updated code generation tools for Rust library to latest stable releases
  (#​486
• Updated code generation tools for Typescript library to latest stable releases
  (#​488

---

Configuration

📅 Schedule: Branch creation - "every 3 weeks on Monday" (UTC), 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.

---

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

---

This PR was generated by Mend Renovate. View the repository job log.