Preserve ABI whether the module signing support is enabled or not

When disabling module signing support, the sig_ok field of struct module is dropped. This causes the CRC in Modules.symvers for each symbol accepting a struct module to change, since genksyms derives the CRC by recursively checking the definition of each parameter.

This in turn means that when disabling modules signing support the debian package build fails because the CRC checked by the ABI step in buildcheck.py won't match the reference.

By making the inclusion of the sig_ok symbol unconditional the ABI is now preserved.

This MR also contains a largely cosmetic fix to revert a spurious change introduced in the last pull from upstream that should minimize merge conflicts in the future.

The MR also contains a patch to drop the cloud images since we don't use them and they were failing due to some other ABI change I have not investigated.