Use dynamic imports for jszip (#5593)

Once we switch to esbuild, this will fix #817. With Webpack it doesn't
appear to quite do it, maybe because of the type imports.

Bundle chunking with esbuild after this fix:

<img width="3120" height="1600" alt="Screenshot 2025-09-04 at 10 42
21 AM"
src="https://github.com/user-attachments/assets/d1579b79-4052-408e-9adf-25def19f74e5"
/>

Author: mstange

src/actions/receive-profile.ts

@@ -3,7 +3,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 import { oneLine } from 'common-tags';
 import queryString from 'query-string';
-import JSZip from 'jszip';
+import type JSZip from 'jszip';
 import {
   insertExternalMarkersIntoProfile,
   insertExternalPowerCountersIntoProfile,
@@ -1045,6 +1045,7 @@ async function _extractZipFromResponse(
   // that comes from this realm.
   const typedBuffer = new Uint8Array(buffer);
   try {
+    const JSZip = await import('jszip');
     const zip = await JSZip.loadAsync(typedBuffer);
     // Catch the error if unable to load the zip.
     return zip;
@@ -1235,6 +1236,7 @@ export function retrieveProfileFromFile(
       if (_deduceContentType(file.name, file.type) === 'application/zip') {
         // Open a zip file in the zip file viewer
         const buffer = await fileReader(file).asArrayBuffer();
+        const JSZip = await import('jszip');
         const zip = await JSZip.loadAsync(buffer);
         await dispatch(receiveZipFile(zip));
       } else {