automation: Update matrix-synapse Docker tag to v1.81.0

This MR contains the following updates:

Package	Update	Change
matrix-synapse	minor	1.76.0 -> 1.81.0

---

⚠ Dependency Lookup Warnings ⚠

Warnings were logged while processing this repo. Please check the Dependency Dashboard for more information.

---

Release Notes

matrix-org/synapse

v1.81.0

Compare Source

===========================

Synapse now attempts the versioned appservice paths before falling back to the legacy paths. Usage of the legacy routes should be considered deprecated.

Additionally, Synapse has supported sending the application service access token via the Authorization header since v1.70.0. For backwards compatibility it is also sent as the access_token query parameter. This is insecure and should be considered deprecated.

A future version of Synapse (v1.88.0 or later) will remove support for legacy application service routes and query parameter authorization.

No significant changes since 1.81.0rc2.

v1.80.0

Compare Source

===========================

No significant changes since 1.80.0rc2.

v1.79.0

Compare Source

===========================

No significant changes since 1.79.0rc2.

v1.78.0

Compare Source

===========================

Bugfixes

• Fix a bug introduced in Synapse 1.76 where 5s delays would occasionally occur in deployments using workers. (#​15150)

v1.77.0

Compare Source

===========================

No significant changes since 1.77.0rc2.

---

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 MR becomes conflicted, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this MR and you won't be reminded about this update again.

---

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

---

This MR has been generated by Renovate Bot.