tests: use stable MAS integration in Synapse (#30473)

* tests: use stable MAS integration in Synapse

* Automatically follow MAS main branch

* Update the pinned Synapse container image to latest develop

* Update element-web-playwright-common to 1.4.5

* Fix the typing of the MAS config

* Update playwright-common to 1.4.6

* Use the modern MAS -> Synapse API

* Relax MAS rate limiting

* Revert using the modern API explicitly, it is now the default

* Better adjust the MAS rate limits

playwright/testcontainers/mas.ts

@@ -0,0 +1,24 @@
+/*
+Copyright 2025 New Vector Ltd.
+
+SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only OR LicenseRef-Element-Commercial
+Please see LICENSE files in the repository root for full details.
+*/
+
+import {
+    MatrixAuthenticationServiceContainer as BaseMatrixAuthenticationServiceContainer,
+    type StartedPostgreSqlContainer,
+} from "@element-hq/element-web-playwright-common/lib/testcontainers";
+
+const TAG = "main@sha256:ee8ce7523f6aeeee9abacb00021428f6f864347581ae23feb17303e55f633f13";
+
+/**
+ * MatrixAuthenticationServiceContainer which freezes the docker digest to
+ * stabilise tests, updated periodically by the `playwright-image-updates.yaml`
+ * workflow.
+ */
+export class MatrixAuthenticationServiceContainer extends BaseMatrixAuthenticationServiceContainer {
+    public constructor(db: StartedPostgreSqlContainer) {
+        super(db, `ghcr.io/element-hq/matrix-authentication-service:${TAG}`);
+    }
+}