Fixes <https://issues.guix.gnu.org/52766>.
Reported by Michael Rohleder <mike@rohleder.de>.
* gnu/machine/ssh.scm (<machine-ssh-configuration>)[safety-checks?]: New
field.
(machine-check-file-system-availability): Return the empty list when
'safety-checks?' is false.
(machine-check-initrd-modules): Likewise.
* doc/guix.texi (Invoking guix deploy): Document it.