chromium with a higher packfile size limit

Most occurences of https://sentry.softwareheritage.org/share/issue/bbcb3aef5b974dac9a3194f7bf8ede87/ happen on chromium forks.

Now that we have fork detection; a single successful load of https://github.com/chromium/chromium might unstuck all its forks; unfortunately we cannot load that repository either, not even from its previous full snapshot.

I think we should try loading https://github.com/chromium/chromium manually as a one-time thing to get it going again (and future loads of this repository should success too, assuming we visit it often enough).

Migrated from T4283 (view on Phabricator)