Remove obsolete "Service Worker Fallback Required" code.
Remove obsolete "Service Worker Fallback Required" code.

This is no longer emitted by Chromium since OOR-CORS was launched. The
code in Chromium was removed in
https://chromium-review.googlesource.com/c/chromium/src/+/2397458

Bug: chromium:1053866
Change-Id: I06740c5cb6f131924f6e31f695ad0418246bab6c
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/2831111
Reviewed-by: Benedikt Meurer <024a1e0af501338d11c3b837c6193d11c140d792@chromium.org>
Commit-Queue: Matt Falkenhagen <ac6d70dd368fdc5b0570ff3c80ed333d4513566a@chromium.org>

ChromeDevTools/devtools-frontend,ChromeDevTools/devtools-frontend,ChromeDevTools/devtools-frontend,ChromeDevTools/devtools-frontend,ChromeDevTools/devtools-frontend,ChromeDevTools/devtools-frontend