[Flatpak][aarch64] All tabs crash after update

Hey, LibreWolf development team!

My symptoms seem related to those observed in issue #37 (closed). I'm running the latest version of the flatpak from flathub on aarch64, Asahi Linux. After upgrading, whenever I open LibreWolf, all tabs I open crash immediately. Looks like there is some debug output:

[edtwardy@Hostname ~]$ flatpak run io.gitlab.librewolf-community
defaults/preferences/firefox.js:6: prefs parse error: expected ',' after pref name
console.error: BroadcastService:
  receivedBroadcastMessage: handler for
  remote-settings/monitor_changes
  threw error:
  Message: Error: Polling for changes failed: The URI is malformed..
  Stack:
    remoteSettingsFunction/remoteSettings.pollChanges@resource://services-settings/remote-settings.js:334:13

JavaScript error: resource://gre/modules/PromiseWorker.jsm, line 106: Error: Could not get children of file(/home/edtwardy/.var/app/io.gitlab.librewolf-community/cache/librewolf/k583dt7h.default-release/thumbnails) because it does not exist

I can't find firefox.js anywhere on the system, so unfortunately I couldn't inspect it for any syntax errors. I believe I unintentionally caused the second issue ("Could not get children of..."). While I was attempting to debug the first issue, I thought I could maybe delete the cache file under ~/.var/app--although it looks like that made the issue worse, and I'm not sure how to proceed to resolve it.

Thanks very much for your help!