chore(deps): update guillaumefalourd/branch-exists action to v1.2

This PR contains the following updates:

| Package | Update | Change |
|---|---|---|
| [element-hq/synapse](https://github.com/element-hq/synapse) | minor | `v1.149.1` → `v1.150.0` |

---

### Release Notes

<details>
<summary>element-hq/synapse (element-hq/synapse)</summary>

### [`v1.150.0`](https://github.com/element-hq/synapse/releases/tag/v1.150.0)

[Compare Source](https://github.com/element-hq/synapse/compare/v1.149.1...v1.150.0)

### Synapse 1.150.0 (2026-03-24)

No significant changes since 1.150.0rc1.

### Synapse 1.150.0rc1 (2026-03-17)

#### Features

- Add experimental support for the [MSC4370](https://github.com/matrix-org/matrix-spec-proposals/pull/4370) Federation API `GET /extremities` endpoint. ([#&#8203;19314](https://github.com/element-hq/synapse/issues/19314))
- [MSC4140: Cancellable delayed events](https://github.com/matrix-org/matrix-spec-proposals/pull/4140): When persisting a delayed event to the timeline, include its `delay_id` in the event's `unsigned` section in `/sync` responses to the event sender. ([#&#8203;19479](https://github.com/element-hq/synapse/issues/19479))
- Expose [MSC4354 Sticky Events](https://github.com/matrix-org/matrix-spec-proposals/pull/4354) over the legacy (v3) /sync API. ([#&#8203;19487](https://github.com/element-hq/synapse/issues/19487))
- When Matrix Authentication Service (MAS) integration is enabled, allow MAS to set the user locked status in Synapse. ([#&#8203;19554](https://github.com/element-hq/synapse/issues/19554))

#### Bugfixes

- Fix `Build and push complement image` CI job pointing to non-existent image. ([#&#8203;19523](https://github.com/element-hq/synapse/issues/19523))
- Fix a bug introduced in v1.26.0 that caused deactivated, erased users to not be removed from the user directory. ([#&#8203;19542](https://github.com/element-hq/synapse/issues/19542))

#### Improved Documentation

- In the Admin API documentation, always express path parameters as `/<param>` instead of as `/$param`. ([#&#8203;19307](https://github.com/element-hq/synapse/issues/19307))
- Update docs to clarify `outbound_federation_restricted_to` can also be used with the [Secure Border Gateway (SBG)](https://element.io/en/server-suite/secure-border-gateways). ([#&#8203;19517](https://github.com/element-hq/synapse/issues/19517))
- Unify Complement developer docs. ([#&#8203;19518](https://github.com/element-hq/synapse/issues/19518))

#### Internal Changes

- Put membership updates in a background resumable task when changing the avatar or the display name. ([#&#8203;19311](https://github.com/element-hq/synapse/issues/19311))
- Add in-repo Complement test to sanity check Synapse version matches git checkout (testing what we think we are). ([#&#8203;19476](https://github.com/element-hq/synapse/issues/19476))
- Migrate `dev` dependencies to [PEP 735](https://peps.python.org/pep-0735/) dependency groups. ([#&#8203;19490](https://github.com/element-hq/synapse/issues/19490))
- Remove the optional `systemd-python` dependency and the `systemd` extra on the `synapse` package. ([#&#8203;19491](https://github.com/element-hq/synapse/issues/19491))
- Avoid re-computing the event ID when cloning events. ([#&#8203;19527](https://github.com/element-hq/synapse/issues/19527))
- Allow caching of the `/versions` and `/auth_metadata` public endpoints. ([#&#8203;19530](https://github.com/element-hq/synapse/issues/19530))
- Add a few labels to the number groupings in the `Processed request` logs. ([#&#8203;19548](https://github.com/element-hq/synapse/issues/19548))

</details>

---

### Configuration

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---

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---

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Reviewed-on: https://gitea.alexlebens.dev/alexlebens/infrastructure/pulls/5040
Co-authored-by: Renovate Bot <renovate-bot@alexlebens.net>
Co-committed-by: Renovate Bot <renovate-bot@alexlebens.net>

clusters/cl01tl/helm/matrix-synapse/Chart.yaml

@@ -81,4 +81,4 @@ dependencies:
     repository: oci://harbor.alexlebens.net/helm-charts
 icon: https://cdn.jsdelivr.net/gh/selfhst/icons/png/matrix.png
 # renovate: datasource=github-releases depName=element-hq/synapse
-appVersion: v1.149.1
+appVersion: v1.150.0