Fix this in Mocha it

This custom declaration leaks into all of DevTools (a problem we should
solve more broadly) and causes noise in tests where we rely on the
`this` to set timeouts, etc.

Bug: none
Change-Id: I5253787e8e3c494540c4768a1c48c7b4bd0be444
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/6308827
Commit-Queue: Nikolay Vitkov <[email protected]>
Commit-Queue: Jack Franklin <[email protected]>
Reviewed-by: Nikolay Vitkov <[email protected]>
Auto-Submit: Jack Franklin <[email protected]>

Author: jackfranklin

test/e2e_non_hosted/types.d.ts

@@ -1,4 +1,3 @@
-
 import type {Platform} from '../conductor/platform.js';
 
 import type {BrowserSettings, BrowserWrapper} from './shared/browser-helper.js';
@@ -30,6 +29,6 @@ declare global {
     }
 
     /* eslint-disable-next-line @typescript-eslint/no-explicit-any */
-    export type TestCallbackWithState = (state: State) => PromiseLike<any>;
+    export type TestCallbackWithState = (this: Mocha.Context, state: State) => PromiseLike<any>;
   }
 }