All iOS devices since the iPhone 5S support ARMv8 (64-bit).
The last iOS version supported on ARMv7 devices is 10.x, which is
too old to run Godot 4.0 projects since the minimum supported
iOS version is 11.0.
We often hit "Too Many Requests" errors when uploading the cache with
`actions/cache` because there's a limit of 10 GB every 5 minutes, and we can
easily go over it when we amend or merge several PRs in a short timespan.
This will make the CI artifacts less useful for debugging crashes but there's
no real way around this.
... on all platforms but MSVC, as it still has a number of unsolved warnings
in its `/Wall` level. Some of it might be valid, others might be overkill,
this needs further assessment and fixes. (We could also change the `extra`
level to `/W4` on MSVC if that's more meaningful.)