Update dependency doorkeeper to v5.7.0

[renovate]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
doorkeeper (changelog)	5.6.9 -> 5.7.0

---

Release Notes

doorkeeper-gem/doorkeeper (doorkeeper)

v5.7.0

• [#​1696] Add missing #issued_token method to OAuth::TokenResponse
• [#​1697] Allow a TokenResponse body to be customized (memoize response body).
• [#​1702] Fix bugs for error response in the form_post and error view
• [#​1660] Custom access token attributes are now considered when finding matching tokens (fixes #​1665).
  Introduce revoke_previous_client_credentials_token configuration option.

---

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.

---

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

---

This PR has been generated by Mend Renovate. View repository job log here.