Update dependency typescript to v6 (#32927)

* Update dependency typescript to v6

* Switch to unplugin-vts

Workaround for https://github.com/qmhc/unplugin-dts/issues/467

And tweak tsconfigs

* tweak tsconfig

* Make tsc happy

---------

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
Co-authored-by: Michael Telatynski <7t3chguy@gmail.com>

apps/web/src/@types/css.d.ts

@@ -0,0 +1,8 @@
+/*
+Copyright 2026 Element Creations 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.
+*/
+
+declare module "*.css";

apps/web/src/@types/global.d.ts

@@ -8,7 +8,6 @@ Please see LICENSE files in the repository root for full details.
 
 // eslint-disable-next-line no-restricted-imports
 import "matrix-js-sdk/src/@types/global"; // load matrix-js-sdk's type extensions first
-import "@types/modernizr";
 
 import type { ModuleLoader } from "@element-hq/element-web-module-api";
 import type { logger } from "matrix-js-sdk/src/logger";
@@ -186,14 +185,6 @@ declare global {
         readonly port: MessagePort;
     }
 
-    /**
-     * In future, browsers will support focusVisible option.
-     * See https://developer.mozilla.org/en-US/docs/Web/API/HTMLElement/focus#focusvisible
-     */
-    interface FocusOptions {
-        focusVisible: boolean;
-    }
-
     // https://github.com/microsoft/TypeScript/issues/28308#issuecomment-650802278
     function registerProcessor(
         name: string,

apps/web/src/@types/pcss.d.ts

@@ -0,0 +1,8 @@
+/*
+Copyright 2026 Element Creations 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.
+*/
+
+declare module "*.pcss";