Live reload in offline mode does not reflect updated frontend assets

[joheriks]

To reproduce:

1. Start a Vaadin PWA and go to a client-side view in Chrome
2. Go offline via Chrome devtools
3. Make a modification to the client-side TS
4. Observe that the browser automatically refreshes, but the front-end is not up-to-date with the changes in the previous step. After waiting a couple of seconds and manually refreshing, the front-end is up-to-date.

Similar to https://github.com/vaadin/flow/issues/9182, but in offline mode. The front-end cached assets are not updated fast enough by workbox-webpack-plugin. Should investigate how to trigger manual update of the precached assets from the gizmo, or alternatively disable live reload in offine mode if that is not feasible.

[haijian-vaadin]

Check after vaadin/hilla#294 is closed, to see if this ticket would be fixed by that. If not, then we disable the live reload in offline mode.