Device dehydration: remove .well-known check (#29404)

* Device dehydrateion: remove .well-known check

Per #29387, this is redundant

* Update src/utils/device/dehydration.ts

Co-authored-by: Michael Telatynski <7t3chguy@gmail.com>

---------

Co-authored-by: Michael Telatynski <7t3chguy@gmail.com>

Author: richvdh

playwright/e2e/crypto/dehydration.spec.ts

@@ -22,18 +22,6 @@ test.use({
             msc3814_enabled: true,
         },
     },
-    config: async ({ config, context }, use) => {
-        const wellKnown = {
-            ...config.default_server_config,
-            "org.matrix.msc3814": true,
-        };
-
-        await context.route("https://localhost/.well-known/matrix/client", async (route) => {
-            await route.fulfill({ json: wellKnown });
-        });
-
-        await use(config);
-    },
 });
 
 test.describe("Dehydration", () => {

src/utils/device/dehydration.ts

@@ -7,34 +7,12 @@ Please see LICENSE files in the repository root for full details.
 */
 
 import { logger } from "matrix-js-sdk/src/logger";
-import { type CryptoApi, type StartDehydrationOpts } from "matrix-js-sdk/src/crypto-api";
+import { type StartDehydrationOpts } from "matrix-js-sdk/src/crypto-api";
 
 import type { MatrixClient } from "matrix-js-sdk/src/matrix";
 
 /**
- * Check if device dehydration is enabled.
- *
- * Note that this doesn't necessarily mean that device dehydration has been initialised
- * (yet) on this client; rather, it means that the server supports it, the crypto backend
- * supports it, and the application configuration suggests that it *should* be
- * initialised on this device.
- *
- * Dehydration can currently only be enabled by setting a flag in the .well-known file.
- */
-async function deviceDehydrationEnabled(client: MatrixClient, crypto: CryptoApi | undefined): Promise<boolean> {
-    if (!crypto) {
-        return false;
-    }
-    if (!(await crypto.isDehydrationSupported())) {
-        return false;
-    }
-    const wellknown = await client.waitForClientWellKnown();
-    return !!wellknown?.["org.matrix.msc3814"];
-}
-
-/**
- * If dehydration is enabled (i.e., it is supported by the server and enabled in
- * the configuration), rehydrate a device (if available) and create
+ * If dehydration is supported by the server, rehydrate a device (if available) and create
  * a new dehydrated device.
  *
  * @param client - MatrixClient to use for the operation
@@ -45,8 +23,8 @@ export async function initialiseDehydrationIfEnabled(
     opts: StartDehydrationOpts = {},
 ): Promise<void> {
     const crypto = client.getCrypto();
-    if (await deviceDehydrationEnabled(client, crypto)) {
-        logger.log("Device dehydration enabled");
-        await crypto!.startDehydration(opts);
+    if (crypto && (await crypto.isDehydrationSupported())) {
+        logger.debug("Starting device dehydration");
+        await crypto.startDehydration(opts);
     }
 }