Remove wait_for_key_rotation_ms config option

I learned that makeKeyDelay has been deprecated in matrix-js-sdk ever since the switch to the new encryption manager, so this config option has no effect.

vite-embedded.config.ts

@@ -6,7 +6,6 @@ Please see LICENSE in the repository root for full details.
 */
 
 import { defineConfig, mergeConfig } from "vite";
-import generateFile from "vite-plugin-generate-file";
 
 import fullConfig from "./vite.config.ts";
 
@@ -19,19 +18,6 @@ export default defineConfig((env) =>
     defineConfig({
       base, // Use relative URLs to allow the app to be hosted under any path
       publicDir: false, // Don't serve the public directory which only contains the favicon
-      plugins: [
-        generateFile([
-          {
-            type: "json",
-            output: "./config.json",
-            data: {
-              matrix_rtc_session: {
-                wait_for_key_rotation_ms: 5000,
-              },
-            },
-          },
-        ]),
-      ],
     }),
   ),
 );