meson: Always build bootctl

bootctl is rather useful to have, even if on a system without UEFI,
as it has a number of verbs that are unrelated to UEFI (e.g kernel-identify),
and more importantly, it supports --root to operate on directory trees
(which could be intended to be deployed on UEFI) so let's make sure we
always build it.

shell-completion/zsh/meson.build

@@ -27,7 +27,7 @@ items = [['_busctl',                   ''],
          ['_sd_outputmodes',           ''],
          ['_sd_unit_files',            ''],
          ['_sd_machines',              ''],
-         ['_bootctl',                  'ENABLE_BOOTLOADER'],
+         ['_bootctl',                  ''],
          ['_coredumpctl',              'ENABLE_COREDUMP'],
          ['_hostnamectl',              'ENABLE_HOSTNAMED'],
          ['_localectl',                'ENABLE_LOCALED'],