Upgrade to TypeScript 7 (#34208)

* Upgrade to TypeScript 7

for massive tsc speed gains

Those on WebStorm will want to upgrade to EAP to reap the benefits of the new TSGo compiler

Some things (module-api & shared-components) which utilise unplugin-dts (and api-extractor) need to hold a copy of ts6 for its conventional lib format and API. TS7 ships with no API until TS7.1.

Other things which use eslint also need ts6 for typescript-eslint.

Some type changes were necessary as TS7 caught some issues.

* Add knip exception

* Fix bad merge

apps/web/tsconfig.json

@@ -23,7 +23,8 @@
             "test-utils": ["./test/test-utils"],
             "test-utils/*": ["./test/test-utils/*"],
             "jest-mock-vitest-adapter": ["./test/setup/adapter.ts"]
-        }
+        },
+        "skipLibCheck": true
     },
     "include": [
         "./node_modules/matrix-js-sdk/src/@types/*.d.ts",