The re-symbolicate button should bypass cached 404 errors

[fqueze]

See https://bugzilla.mozilla.org/show_bug.cgi?id=1758566 for context.

[mstange]

When triggering symbolication from the re-symbolicate button, we could, prior to sending the JSON request to the symbolication API, do some HEAD requests for each of the cached libraries, to https://symbols.mozilla.org/<debugName>/<breakpadID>/<debugName>.sym?_refresh=1.